Kernel Modeling Language Avatar
  1. OMG Specification

Kernel Modeling Language — Open Issues

  • Acronym: KerML
  • Issues Count: 260
  • Description: Issues not resolved
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Issues not resolved

Issues Summary

Key Issue Reported Fixed Disposition Status
KERML_-90 Problem with validateImportTopLevelVisibility constraint KerML 1.0b2 open
KERML_-73 Disallow public imports at root level KerML 1.0b2 open
KERML_-74 Make imports private by default KerML 1.0b2 open
KERML_-88 Problem with the property name "targetFeature" KerML 1.0b2 open
KERML_-37 Add derived property for targetFeature KerML 1.0b1 open
KERML_-46 Serious limitation of textual concrete syntax as model interchange format KerML 1.0b1 open
KERML_-25 XMI and JSON for model libraries KerML 1.0a1 open
KERML_-18 Redundancy in association end multiplicities, ordering, and uniqueness KerML 1.0a1 open
KERML_-19 Context-dependent meanings for feature multiplicity, ordering, and uniqueness KerML 1.0a1 open
KERML_-16 Association participant features, misleading term and textual keyword KerML 1.0a1 open
KERML_-21 Association end features are not necessarily consistent with corresponding features of associated classifiers KerML 1.0a1 open
KERML_-17 Number of association end feature values, semantics KerML 1.0a1 open
KERML_-12 End feature multiplicity textual notation KerML 1.0a1 open
KERML_-20 Nary association end multiplicity, semantics KerML 1.0a1 open
KERML_-4 isReadOnly, semantics KerML 1.0a1 open
KERML_-75 Restrict the functionality of recursive import KerML 1.0b2 open
KERML_-52 Semantic constraint needed for result type of a "constructor" expression KerML 1.0b1 open
KERML_-86 Confusing "Classes" with "Structures" KerML 1.0b1 open
KERML_-57 Time and space life/slice/portion modeling patterns are missing KerML 1.0b1 open
KERML_-70 The OCL for isFeaturedWithin is still not correct KerML 1.0b2 open
KERML_-69 relationship not defined KerML 1.0b2 open
KERML_-67 Invocation of a non-function behavior KerML 1.0b2 open
KERML_-65 isOrdered and isUnique are missing from the reflective abstract mapping KerML 1.0b2 open
KERML_-63 FeatureIdentificationProduction is incorrect KerML 1.0b2 open
KERML_-61 Incorrect binding syntax in Feature Values Semantics KerML 1.0b2 open
KERML_-85 Impossible to specialize (redefine, subset) unnamed features in textual syntax KerML 1.0b2 open
KERML_-26 Some types not given any semantics KerML 1.0a1 open
KERML_-84 Type::directionOf does not handle inheritence from feature chains KerML 1.0b2 open
KERML_-72 Editorial errors in constraints KerML 1.0b2 open
KERML_-83 CollectExpression and SelectExpression should not reference BodyExpressionMember KerML 1.0b2 open
KERML_-68 deriveExpressionResult and deriveFunctionResult should be revised KerML 1.0b2 open
KERML_-59 OCL for checkFeatureParameterRedefinition is wrong KerML 1.0b2 open
KERML_-1 isEnd of the redefining feature must match isEnd of the redefined feature KerML 1.0b1 open
KERML_-58 checkFeatureParameterRedefinition fails for named-argument invocations KerML 1.0b1 open
KERML-308 checkFeatureParameterRedefinition fails for named-argument invocations KerML 1.0b1 open
KERML-306 Time and space life/slice/portion modeling patterns are missing KerML 1.0b1 open
KERML-246 isDerived, semantics KerML 1.0b1 open
KERML-283 Space triggers missings KerML 1.0b1 open
KERML-258 Discrepancy between documentation of Collections library in spec and textual notation file KerML 1.0a1 open
KERML_-56 Space triggers missings KerML 1.0b1 open
KERML_-54 isDerived, semantics KerML 1.0b1 open
KERML_-55 Discrepancy between documentation of Collections library in spec and textual notation file KerML 1.0a1 open
KERML-208 Composite feature values can have more than one owner KerML 1.0b1 open
KERML-233 TimeOf::timeContinuityConstraint might be too restrictive KerML 1.0a1 open
KERML-244 Semantic constraint needed for result type of a "constructor" expression KerML 1.0b1 open
KERML-211 Some syntax in Core has time-dependent semantics KerML 1.0a1 open
KERML-207 Annex A coverage KerML 1.0b1 open
KERML_-51 TimeOf::timeContinuityConstraint might be too restrictive KerML 1.0a1 open
KERML_-50 Some syntax in Core has time-dependent semantics KerML 1.0a1 open
KERML_-49 Composite feature values can have more than one owner KerML 1.0b1 open
KERML_-48 Annex A coverage KerML 1.0b1 open
KERML-205 Serious limitation of textual concrete syntax as model interchange format KerML 1.0b1 open
KERML-168 Ambiguity In Directionality InOut semantics KerML 1.0b1 open
KERML-197 Redefining features sometimes must respecify metaproperties even when they are the same as those of the redefined feature KerML 1.0b1 open
KERML-206 Read only, misleading keyword, metaproperty name KerML 1.0b1 open
KERML_-44 Ambiguity In Directionality InOut semantics KerML 1.0b1 open
KERML_-47 Read only, misleading keyword, metaproperty name KerML 1.0b1 open
KERML_-45 Redefining features sometimes must respecify metaproperties even when they are the same as those of the redefined feature KerML 1.0b1 open
KERML-159 Association end feature description missing simple example and equivalence to related types KerML 1.0b1 open
KERML-126 Type::inheritedMemberships OCL is missing KerML 1.0a1 open
KERML-163 Root namespaces restricted to one single file KerML 1.0b1 open
KERML-157 TransitionPerformance modeling pattern more general than needed, not aligned with SysML::TransitionUsage KerML 1.0a1 open
KERML-127 Add validateSubsettingTypeConformance constraint KerML 1.0b1 open
KERML_-42 Association end feature description missing simple example and equivalence to related types KerML 1.0b1 open
KERML_-43 Root namespaces restricted to one single file KerML 1.0b1 open
KERML_-41 TransitionPerformance modeling pattern more general than needed, not aligned with SysML::TransitionUsage KerML 1.0a1 open
KERML_-40 Add validateSubsettingTypeConformance constraint KerML 1.0b1 open
KERML_-39 Type::inheritedMemberships OCL is missing KerML 1.0a1 open
KERML-97 validateAssociationStructureIntersection seems vacuous KerML 1.0b1 open
KERML-124 Inherited multiplicities, semantics KerML 1.0b1 open
KERML-123 Add derived property for targetFeature KerML 1.0b1 open
KERML-116 FeatureMembership owningType attribute ambiguity KerML 1.0b1 open
KERML-121 KerML Libraries' elements shall have an elementId defined KerML 1.0a1 open
KERML_-36 KerML Libraries' elements shall have an elementId defined KerML 1.0a1 open
KERML_-35 FeatureMembership owningType attribute ambiguity KerML 1.0b1 open
KERML_-38 Inherited multiplicities, semantics KerML 1.0b1 open
KERML_-34 validateAssociationStructureIntersection seems vacuous KerML 1.0b1 open
KERML-76 Association ends can have more than one type KerML 1.0a1 open
KERML-93 Default for the first operand of a classification expression KerML 1.0a1 open
KERML-63 Invariants only hold when evaluated KerML 1.0a1 open
KERML-57 Some package-level features are mandatory KerML 1.0a1 open
KERML-58 Feature values do not specify when their expressions are evaluated KerML 1.0a1 open
KERML_-29 Some package-level features are mandatory KerML 1.0a1 open
KERML_-32 Association ends can have more than one type KerML 1.0a1 open
KERML_-30 Feature values do not specify when their expressions are evaluated KerML 1.0a1 open
KERML_-31 Invariants only hold when evaluated KerML 1.0a1 open
KERML_-33 Default for the first operand of a classification expression KerML 1.0a1 open
KERML-52 Some types not given any semantics KerML 1.0a1 open
KERML-51 XMI and JSON for model libraries KerML 1.0a1 open
KERML-55 Connector ends cannot give smaller lower multiplicity than their association ends KerML 1.0a1 open
KERML-53 Machine readable project interchange file(s) for language description examples KerML 1.0a1 open
KERML_-27 Machine readable project interchange file(s) for language description examples KerML 1.0a1 open
KERML_-28 Connector ends cannot give smaller lower multiplicity than their association ends KerML 1.0a1 open
KERML-40 Nary association end multiplicity, semantics KerML 1.0a1 open
KERML-41 Association end features are not necessarily consistent with corresponding features of associated classifiers KerML 1.0a1 open
KERML-47 Sufficiency missing for some library types KerML 1.0a1 open
KERML-48 Conditions missing for some sufficient library types KerML 1.0a1 open
KERML-50 Performance & Object self redefinition missing in specification document KerML 1.0a1 open
KERML_-24 Performance & Object self redefinition missing in specification document KerML 1.0a1 open
KERML_-22 Sufficiency missing for some library types KerML 1.0a1 open
KERML_-23 Conditions missing for some sufficient library types KerML 1.0a1 open
KERML-37 Context-dependent meanings for feature multiplicity, ordering, and uniqueness KerML 1.0a1 open
KERML-36 Redundancy in association end multiplicities, ordering, and uniqueness KerML 1.0a1 open
KERML-35 Number of association end feature values, semantics KerML 1.0a1 open
KERML-34 Association participant features, misleading term and textual keyword KerML 1.0a1 open
KERML-29 Succession end multiplicity defaults not documented KerML 1.0a1 open
KERML-26 End feature multiplicity textual notation KerML 1.0a1 open
KERML-27 Some bindings have optional connector end multiplicities KerML 1.0a1 open
KERML-28 Decision/MergePerformance element descriptions give incorrect modeling pattern KerML 1.0a1 open
KERML_-15 Succession end multiplicity defaults not documented KerML 1.0a1 open
KERML_-13 Some bindings have optional connector end multiplicities KerML 1.0a1 open
KERML_-14 Decision/MergePerformance element descriptions give incorrect modeling pattern KerML 1.0a1 open
KERML-8 Type union, intersection, difference semantics KerML 1.0a1 open
KERML-9 isSufficient, semantics, expressiveness KerML 1.0a1 open
KERML-11 Steps are not always time enclosed KerML 1.0a1 open
KERML-10 direction, semantics KerML 1.0a1 open
KERML_-8 Type union, intersection, difference semantics KerML 1.0a1 open
KERML_-11 Steps are not always time enclosed KerML 1.0a1 open
KERML_-9 isSufficient, semantics, expressiveness KerML 1.0a1 open
KERML_-10 direction, semantics KerML 1.0a1 open
KERML-6 isAbstract, semantics KerML 1.0a1 open
KERML-5 isPortion, semantics KerML 1.0a1 open
KERML-4 isComposite, semantics KerML 1.0a1 open
KERML-2 Dynamic multiplicity, semantics KerML 1.0a1 open
KERML-3 isReadOnly, semantics KerML 1.0a1 open
KERML_-3 Dynamic multiplicity, semantics KerML 1.0a1 open
KERML_-7 isAbstract, semantics KerML 1.0a1 open
KERML_-6 isPortion, semantics KerML 1.0a1 open
KERML_-5 isComposite, semantics KerML 1.0a1 open
KERML-1 Classifier multiplicity, semantics KerML 1.0a1 open
KERML_-2 Classifier multiplicity, semantics KerML 1.0a1 open
KERML-15 Names validatePackageFilterIsBoolean and validatePackageFilterIsModelEvaluable are wrong KerML 1.0a1 open
KERML-14 validateItemFlowItemFeature documentation is wrong KerML 1.0a1 open
KERML-16 Rename validateDatatypeSpecialization to validateDataTypeSpecialization KerML 1.0a1 open
KERML-30 List of symbols incomplete KerML 1.0a1 open
KERML-32 Validation constraints are missing in the SysML abstract syntax KerML 1.0a1 open
KERML-65 Typo in description of Connector::targetFeature KerML 1.0a1 open
KERML-17 The OCL for checkFeatureEndRedefinition is wrong KerML 1.0a1 open
KERML-13 validateRedefinitionFeaturingTypes documentation and constraint are wrong KerML 1.0a1 open
KERML-60 7.4.1 Kernel Overview: Occurence instead of Object superclass KerML 1.0a1 open
KERML-78 Some Feature constraints have no description KerML 1.0a1 open
KERML-31 Typo in Grammar KerML 1.0a1 open
KERML-80 Incorrect OCL for validateFeatureChainingFeatureNotOne and validateFeatureChainingFeaturesNotSelf KerML 1.0a1 open
KERML-64 Typo in 7.4.7.2 KerML 1.0a1 open
KERML-89 The checkFeatureValuationSpecialization constraint is incorrect KerML 1.0a1 open
KERML-19 The checkFeatureEndSpecialization constraint should apply to Connectors as well as Associations KerML 1.0a1 open
KERML-83 OCL errors in specialization constraints KerML 1.0a1 open
KERML-95 validateTypeAtMostOneConjugator OCL is wrong KerML 1.0b1 open
KERML-94 The description of deriveFeatureReferenceExpressionReferent is wrong KerML 1.0a1 open
KERML-101 NamespaceImport Description Incorrect KerML 1.0b1 open
KERML-107 validateSpecificationSpecificNotConjugated Typo and over Constraint KerML 1.0b1 open
KERML-102 OwningMembership Description ownedMemberElement typo KerML 1.0b1 open
KERML-113 deriveFeatureOwnedSubsetting text references wrong attribute KerML 1.0b1 open
KERML-103 deriveElementIsLibraryElement Typo KerML 1.0b1 open
KERML-115 FeatureMembership Description Typo KerML 1.0b1 open
KERML-100 Namespace Description Textual Errors KerML 1.0b1 open
KERML-96 validateSpecializationSpecificNotConjugated documentation is wrong KerML 1.0b1 open
KERML-99 deriveMembershipMemberElementId text elementId typo KerML 1.0b1 open
KERML-18 Semantic constraints for subtypes of LiteralExpression are missing KerML 1.0a1 open
KERML-118 deriveFeatureFeaturingType conflicts with owningType KerML 1.0b1 open
KERML-12 OCL errors in validateFeatureChainingFeatureNotOne and validateFeatureChainingFeaturesNotSelf KerML 1.0a1 open
KERML-117 deriveTypeFeatureMembership incorrect unioning KerML 1.0b1 open
KERML-122 validateClassSpecialization is too strict KerML 1.0b1 open
KERML-151 deriveFeatureType is not correct KerML 1.0b1 open
KERML-112 deriveTypeOwned TypeRelationship constraints have incomplete OCL KerML 1.0b1 open
KERML-77 Problems with IfThenElsePerformance KerML 1.0a1 open
KERML-38 Binary association ends always unique KerML 1.0a1 open
KERML-177 Legacy, so incorrect, wording in Anything Description KerML 1.0b1 open
KERML-175 Natural unnecessary explicit general type declaration KerML 1.0b1 open
KERML-88 BaseFunctions::',' has a bad parameter declaration KerML 1.0a1 open
KERML-176 Base Overview Typo KerML 1.0b1 open
KERML-180 Occurrences Overview Typo KerML 1.0b1 open
KERML-20 Validation constraints are missing in the KerML abstract syntax KerML 1.0a1 open
KERML-184 Update Kernel Model Libraries for validateFeatureValueOverriding constraint KerML 1.0b1 open
KERML-195 Transfer sourceOutput and targetInput directions KerML 1.0b1 open
KERML-227 Documentation of features in Transfers library model is wrong KerML 1.0b1 open
KERML-188 DataFunctions::Min and Max should not be capitalized KerML 1.0b1 open
KERML-198 Wrong documentation format for class Occurrence in Semantic Library KerML 1.0b1 open
KERML-42 Occurrences can be data values KerML 1.0a1 open
KERML-25 Reflective KerML abstract syntax model has inconsistencies KerML 1.0a1 open
KERML-59 KerML 7.4.7.2 Behavior Declaration: last example KerML 1.0a1 open
KERML-178 Anything.self subsetting Inconsistent declaration with Base.kerml declaration KerML 1.0b1 open
KERML-182 Update Kernel Semantic Library for validateRedefinitionDirectionConformance constraint KerML 1.0b1 open
KERML-24 Connector declaration does not allow a feature value KerML 1.0a1 open
KERML-56 Universal features can have many values KerML 1.0a1 open
KERML-43 Performances can be objects, behaviors can be structures KerML 1.0a1 open
KERML-44 Spatial links can be occurrences KerML 1.0a1 open
KERML-54 Subsetting::/owningType is mandatory KerML 1.0a1 open
KERML-39 Link participant feature called an association end KerML 1.0a1 open
KERML-90 The MetadataFeature::metaclass multiplicity is too restrictive KerML 1.0a1 open
KERML-105 Car necessary and sufficiency example KerML 1.0b1 open
KERML-104 Type Membership Multiplicity text conflict KerML 1.0b1 open
KERML-62 Occurrences do not identify local spatial frame KerML 1.0a1 open
KERML-158 InsideOf association end feature redefines cross feature KerML 1.0b1 open
KERML-138 oclAsType applied to resolveGlobal KerML 1.0b1 open
KERML-109 Textual Syntax allows multiple ConjugationParts on a Type KerML 1.0b1 open
KERML-106 Protected membership inheritance through Specialization type KerML 1.0b1 open
KERML-111 Disjoining textual notation typo on disjoiningType KerML 1.0b1 open
KERML-108 Conjugation Textual Redundant Word KerML 1.0b1 open
KERML-114 FeatureDeclaration ConjugationPart lexical element incorrect reference KerML 1.0b1 open
KERML-170 checkFeatureSubobjectSpecialization incorrect Font KerML 1.0b1 open
KERML-167 Typo in Conjugation Description KerML 1.0b1 open
KERML-162 Misidentified non-terminals and misspelled non-terminals in the EBNF KerML 1.0b1 open
KERML-169 Feature isDerived metaproperty Typo KerML 1.0b1 open
KERML-160 unknown non-terminal reference in EBNF KerML 1.0b1 open
KERML-164 No production for nonterminal KerML 1.0b1 open
KERML-191 Comment textual syntax defined differently to implementation KerML 1.0b1 open
KERML-190 OwnedExpression missing ConditionalBinaryOperatorExpression KerML 1.0b1 open
KERML-171 Feature Chain relationships are inconsistent with the concrete syntax KerML 1.0b1 open
KERML-189 non-terminal does not exist in the specification KerML 1.0b1 open
KERML-181 Model Interchange Overview Typo KerML 1.0b1 open
KERML-179 checkAssociationStructureSpecialization invalid reference KerML 1.0b1 open
KERML-172 ClassifierDeclaration concrete syntax typo KerML 1.0b1 open
KERML-173 Classifier Description Typo KerML 1.0b1 open
KERML-200 Annex A (Model Execution) minor errors KerML 1.0b1 open
KERML-232 Additional problems with deriveFeatureType KerML 1.0b1 open
KERML-194 validateRedefinitionDirectionConformance does not account for conjugation KerML 1.0b1 open
KERML-236 Association SourceType Cardinality Contradiction KerML 1.0b1 open
KERML-193 Weird Concrete Syntax for ConditionalExpression KerML 1.0b1 open
KERML-192 Many mistakes and differences to implementation KerML 1.0b1 open
KERML-238 No textual syntax or derivation rules for isDirected KerML 1.0b1 open
KERML-237 Link Participant Plurality Typo in OCL KerML 1.0b1 open
KERML-241 Typo in Multiplicity Ranges Semantics KerML 1.0b1 open
KERML-240 Typo in Multiplicities Overview KerML 1.0b1 open
KERML-248 Error in Expression modelLevelEvaluable operation OCL KerML 1.0b1 open
KERML-242 Typo in checkAssociationBinarySpecialization OCL KerML 1.0b1 open
KERML-247 Typo in modelLevelEvaluable Operation text KerML 1.0b1 open
KERML-239 SelfLink::thatThing does not exist in Links Model Library KerML 1.0b1 open
KERML-61 PrimaryExpressionMember production should generate a ParameterMembership KerML 1.0a1 open
KERML-186 Update semantic model of invariants for validateExpressionResultExpressionMembership constraint KerML 1.0b1 open
KERML-260 Definition of property "typing" seems incomplete/inconsistent KerML 1.0b1 open
KERML-249 Typo in Function Abstract Syntax Description KerML 1.0b1 open
KERML-250 Typo in Function Declaration Overview KerML 1.0b1 open
KERML-251 Remove disjointness of LinkObject KerML 1.0b1 open
KERML-49 Some readonly features are intended to have changing values KerML 1.0a1 open
KERML-199 validateMultiplicityRangeBoundResultTypes constraint is too strong KerML 1.0b1 open
KERML-231 LinkObject disjointness is redundant KerML 1.0b1 open
KERML-204 Behavior portions must be classified by the same behavior they are portions of KerML 1.0b1 open
KERML-75 Specify default direction for the ownedParameterMember of a ParameterMembership KerML 1.0a1 open
KERML-21 Add a property for Annotations owned by an AnnotatingElement KerML 1.0a1 open
KERML-259 Reference to nonexistent class (Superclassification) in OCL rule deriveClassifierOwnedSubclassification KerML 1.0b1 open
KERML-154 Directed features inherited from a conjugated type not handled properly KerML 1.0b1 open
KERML-139 OclisKindOf applied to Namespace::resolve() KerML 1.0a1 open
KERML-161 Misspelling KerML 1.0b1 open
KERML-7 isDirected, definition, semantics KerML 1.0a1 open
KERML-23 Follow typographical conventions in the KerML Metamodel clause KerML 1.0a1 open
KERML-22 Name all associations in the KerML abstract syntax KerML 1.0a1 open
KERML-174 DataType Disjointness Clarification KerML 1.0b1 open
KERML-165 Exponentiation should be right-associative KerML 1.0b1 open
KERML-234 Features successors and predecessors of Occurrence should be disjoint KerML 1.0a1 open
KERML-282 Measuring devices for space missing KerML 1.0b1 open
KERML-307 User-defined keywords are not allowed on metadata features KerML 1.0b1 open
KERML-309 package "Interactions TBD" should not be included in the XMI file KerML 1.0b1 open
KERML-45 LinkObject is irreflexive KerML 1.0a1 open
KERML-120 FlowTransferBefore needs end feature declarations KerML 1.0b1 open
KERML-82 checkConnectorTypeFeaturing is not correct KerML 1.0a1 open
KERML-98 Comment Locale not in textual notation KerML 1.0b1 open
KERML-110 Disjoining example conflicts with textual description KerML 1.0b1 open
KERML-125 specializesFromLibrary arguments use inconsistent notation for strings KerML 1.0a1 open
KERML-46 Intersection missing for some multiple specializations KerML 1.0a1 open

Issues Descriptions

Problem with validateImportTopLevelVisibility constraint

  • Key: KERML_-90
  • Status: open   Implementation work Blocked
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    Resolution KERML_-79 to issue KERML_-73, approved in Ballot 1, introduces the new validation constraint validateImportTopLevelVisibility with the OCL:

    importOwningNamespace.owningNamespace = null implies 
        visibility = VisibilityKind::private
    

    However, the check in the OCL needs to be on importOwningNamespace.owner rather than importOwningNamespace.owningNamespace, because a filtered import is parsed as having a nested package that is actually owned via a NamespaceImport relationship rather than a Membership. In this case, the package will not have an owningNamespace, but it will still not be the root namespace, because it has an owner.

  • Reported: KerML 1.0b2 — Wed, 17 Jul 2024 03:52 GMT
  • Updated: Fri, 19 Jul 2024 18:16 GMT

Disallow public imports at root level

  • Key: KERML_-73
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    It is allowable to have imports at the top-level in a root namespace. If such an import is public, then anything so imported becomes visible in the scope of the global namespace, without qualification. This can potentially introduce name resolution ambiguities that makes global namespace resolution much more difficult.

    For example, consider the following three root namespaces (perhaps from separate textual notation files);

    package Namespace1 {
        classifier A;
        classifier B;
    }
    
    public import Namespace1::*;
    package Namespace2 {
       ...
    }
    
    public import Namespace1::*;
    package Namespace3 {
       ...
    }
    

    The classifiers A and B are now globally available not only as Namespace1::A and Namespace1::B from the first root namespace, but also by the unqualified names A and B from both of the other two root namespaces. (And this ambiguity is not invalid according to the global namespace name resolutions rules in 8.2.3.5.4.)

    While it can be useful to be able to import names at the top-level into a root namespace, it does not seem necessary to be able to publicly re-export such names into the global namespace. So, disallowing public imports in the root namespace would simplify global name resolution without really removing any particularly useful functionality.

  • Reported: KerML 1.0b2 — Sun, 5 May 2024 23:30 GMT
  • Updated: Wed, 17 Jul 2024 03:48 GMT

Make imports private by default

  • Key: KERML_-74
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    Currently, the default visibility for an Import relationship is public (see KerML specification, 8.3.2.4.1, Figure 8). This is consistent with the default visibility for Membership relationships. This means that, by default, any memberships that are imported into a namespace are also visible memberships that are "re-exported" out of the importing namespace.

    Now, imports are often used just to make names from on namespace available without qualification within another namespace, with no real intention of re-exporting those names. Nevertheless, unless a modeler explicitly changes the import visibility to private from the default of public, then the names will still all be re-exported anyway. Such re-exporting when unnecessary can have a significant, unintentional impact on the performance of name resolution for a large textually represented model by greatly increasing the space of visible names that need to be searched.

    If, on the other hand, import relationships were private by default, then they could still be easily used for importing into a namespace. However, the modeler would then need to make an explicit decision to change the visibility to public if it is desired to re-export the imported names, with, presumably, an explicit consideration of the consequences of doing so.

  • Reported: KerML 1.0b2 — Mon, 6 May 2024 03:49 GMT
  • Updated: Tue, 16 Jul 2024 22:31 GMT

Problem with the property name "targetFeature"

  • Key: KERML_-88
  • Status: open   Implementation work Blocked
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    Resolution KERML_-82 to issue KERML_-37, approved in FTF2 Ballot 1, resulted in a property targetFeature to the metaclass Feature. Unfortunately, this causes a name conflict with the similar named properties that already exist in Feature subclasses Connector and FeatureChainExpression.

  • Reported: KerML 1.0b2 — Tue, 16 Jul 2024 20:29 GMT
  • Updated: Tue, 16 Jul 2024 20:29 GMT

Add derived property for targetFeature

  • Key: KERML_-37
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    When a Feature has chainingFeatures, then it is sometimes useful to reference that last Feature in the chain in situations in which one would otherwise reference the owning Feature itself if there was no chain. For instance, in a graphical view, an edge with a chained Feature at an end will generally point to the last chainedFeature (possibly nested) rather than the chained Feature itself.

    Currently, this means that it is necessary to check for a feature f whether f.chainingFeature is non-empty and, if so, use f.chainingFeature->last() instead of f. It would be more convenient to have a derived property of Feature (called, say, targetFeature) that would do this automatically, that is, be derived as

    targetFeature = if chainingFeature.isEmpty() then self else chainingFeature->last() end if
    
  • Reported: KerML 1.0b1 — Sun, 16 Jul 2023 20:19 GMT
  • Updated: Tue, 16 Jul 2024 20:20 GMT
  • Attachments:

Serious limitation of textual concrete syntax as model interchange format

  • Key: KERML_-46
  • Status: open  
  • Source: DEKonsult ( Mr. Hans Peter de Koning)
  • Summary:

    The specification in subclause 10.2 lists the textual concrete syntax as one format for model interchange.

    However, the textual concrete syntax does not include syntax for the elementId : UUID property of any element specified in such a model interchange. In general, this makes it impossible to derive the net semantic difference between model interchanges of a pair of revisions (or versions) of the same package represented in this format. The elementId identifiers are necessary to detect whether a change constitutes: (1) a newly created element, (2) an updated element (including a moved element), or (3) a deleted element. In general, it will only be possible to derive the net lexical difference. This limitation holds in particular for unnamed (i.e. anonymous) elements, as well as for elements with name and/or shortName changes.

    It is therefore debatable whether the textual concrete syntax may be designated as a proper model interchange format.

    This limitation of use of the textual concrete syntax as an interchange format should be explicitly addressed through one of the following:

    1. Add an explanation of the limitation in the specification.
    2. Add a facility in the textual concrete syntax to include representation of the elementId for any element. For usability reasons, implementations should provide a capability to show or hide the elementId snippets in the concrete textual notation editor widgets.
  • Reported: KerML 1.0b1 — Sat, 28 Oct 2023 14:22 GMT
  • Updated: Mon, 15 Jul 2024 19:23 GMT

XMI and JSON for model libraries

  • Key: KERML_-25
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Project interchange files (.kpar) were submitted for all model libraries. However, in all cases, these archives only included textual notation model interchange files (.kerml). There should also be normative model library project interchange files in which the models are formatted in XMI and JSON.

  • Reported: KerML 1.0a1 — Fri, 28 Apr 2023 19:51 GMT
  • Updated: Mon, 15 Jul 2024 19:23 GMT

Redundancy in association end multiplicities, ordering, and uniqueness

  • Key: KERML_-18
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    KerML association end textual notation/abstract syntax give multiplicity, ordering, and uniqueness that can be redundantly stated on the corresponding features of associated classifiers (association ends in SysML1.x/UML sense, see KERML-34 about terms), eg, in Occurrences:

    Occurrence::suboccurrences [1..*] {...}
    
    HappensDuring {end shorterOccurrence [1..*] subsets longerOccurrence.suboccurrences;}
    

    making it possible for multiplicities, ordering, and uniqueness to get out synch between the features, and potentially be inconsistent. See kerml-assoc-redundancy-issue-description-v2.pdf slides attached.

  • Reported: KerML 1.0a1 — Wed, 26 Apr 2023 14:35 GMT
  • Updated: Thu, 11 Jul 2024 21:38 GMT
  • Attachments:

Context-dependent meanings for feature multiplicity, ordering, and uniqueness

  • Key: KERML_-19
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    The specification gives Feature::multiplicity, ordering, and uniqueness very different meanings for what it calls "end" features (see KERML-34 for definition of terms) than other features. This requires modelers and tool builders to create special cases in their minds and implementations to accommodate it. It also prevents

    • connector ends from giving smaller lower multiplicity than their association ends (see KERML-55)
    • participant features from specifying how many values they have (see KERML-35)
    • multiplicities from being uniquely specified (see KERML-36).

    Normally feature multiplicity restricts the number of values of a feature, but for association "end" features it restricts the number of values of the corresponding features of associated classifiers (association ends in SysML1.x/UML sense,(see KERML-34 for definition of terms) about terms), see excepts below. For example, in the Product Selection example, the info feature of association Selection has the usual semantics for multiplicity, but the "end" features linkedCart an linkedProduct do not. The same comments apply to end ordering and uniqueness.

    Clause 7.4.5 (Associations) says

    The semantics of multiplicity is different for end features from that for non-end features (as described in 7.3.4.2). The end features of an association determine the participants in the links that are instances of the association and, as such, effectively have multiplicity of "1" relative to the association. But, if an association end has a multiplicity specified other than 1..1, then this is interpreted as follows: For each association end, the multiplicity, ordering and uniqueness constraints specified for that end apply to each set of instance of the association that have the same (single) values for each of the other ends. For a binary association, this corresponds to the multiplicity resulting from "navigating" across the association given a value at one end of the association to the other end of the association.

    Clause 8.4.4.5.1 (Associations) says

    As endFeatures, the associationEnds of an Association are given a special semantics compared to other Features. Even if an associationEnd has a declared multiplicity other than 1..1, the associationEnd is required to effectively have multiplicity 1..1 as a participant in the Link. Note that the Feature Link::participant is declared readonly, meaning that the participants in a link cannot change once the link is created.

    If an associationEnd has a declared multiplicity other than 1..1, then this shall be interpreted as follows: For an Association with N associationEnds, consider the i-th associationEnd ei. The multiplicity, ordering and uniqueness constraints specified for ei apply to each set of instances of the Association that have the same (singleton) values for each of the N-1 associationEnds other than ei.

    Clause 8.3.3.3.3 (Feature) says

    isEnd : Boolean
    Whether or not the this Feature is an end Feature, requiring a different interpretation of the multiplicity of the Feature. An end Feature is always considered to map each domain instance to a single co-domain instance, whether or not a Multiplicity is given for it. If a Multiplicity is given for an end Feature, rather than giving the co-domain cardinality for the Feature as usual, it specifies a cardinality constraint for navigating across the endFeatures of the featuringType of the end Feature.

    That is, if a Type has n endFeatures, then the Multiplicity of any one of those end Features constrains the cardinality of the set of values of that Feature when the values of the other n-1 end Features are held fixed.

  • Reported: KerML 1.0a1 — Wed, 26 Apr 2023 14:47 GMT
  • Updated: Thu, 11 Jul 2024 21:37 GMT
  • Attachments:

Association participant features, misleading term and textual keyword

  • Key: KERML_-16
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    The specification and models carry over the terms "association end" and "participant" from SysML 1.x, leaving the meaning of "participant" as it was, but changing the meaning of "association end" to be same as "participant", and providing no term equivalent to SysML 1.x "association end" (see below). This shift makes KerML/SysML 2 associations difficult to understand and discuss among current SysMLers (judging from experience during the submission process), and probably those new to SysML as well.

    The specification term "association end" refers to what SySML 1.x calls a "participant" property, a property of links (instances of associations) that each identify exactly one of the things being linked by each link. The library element Link has a feature named "participant", with exactly the same meaning as in SysML 1.x, that generalizes "association end" features, such as the source and target features of BinaryLink. The term "association end" in SysML 1.x refers to properties (typically) of associated classes that on each instance of one associated class identify (potentially zero or multiple) instances of the other associated class that are linked by the association. KerML can model these kind of features, but does not give a name for them.

    Clauses 7.4.5 (Associations) and 9.2.3.1 (Links Overview) say

    Associations are classifiers that classify links between things (see 9.2.3.1) At least two owned features of an association must be end features (see 7.3.4.2), its association ends, which identify the things being linked by (at the "ends" of) each link (exactly one thing per end, which might be the same thing).

    The end features of an association determine the participants in the links that are instances of the association and, as such, effectively have multiplicity of "1" relative to the association.

    The participant Feature of Link is the most general associationEnd, identifying the things being linked by (at the "ends" of) each Link (exactly one thing per end, which might be the same things).

    where Association::associationEnds identify participant features.

    The above use of "association end" in the specifiation is reflected in the textual syntax for assocations by the keyword "end" identifying these participant features. Clause 8.4.4.5.1 (Associations) says:

    n-aries have this form:

    uassoc A specializes Links::Link {
    end feature e1 subsets Links::Link::participant;
    end feature e2 subsets Links::Link::participant;
    ...
    end feature eN subsets Links::Link::participant; }
    

    The Link instance for an Association is thus a tuple of participants, where each participant is a single value of an associationEnd of the Association.

    The quoted text above is only about the equivalent of SysML 1.x participant properties, but might seem to current SysMLers to be about something equivalent to SysML 1.x association ends.

  • Reported: KerML 1.0a1 — Wed, 26 Apr 2023 14:09 GMT
  • Updated: Thu, 11 Jul 2024 21:37 GMT

Association end features are not necessarily consistent with corresponding features of associated classifiers

  • Key: KERML_-21
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    The textual and abstract syntaxes (at least) for association end features do not relate to the corresponding ones in the associated classes (association ends in SysML1.x/UML sense, see KERML-34 for term definitions), leaving modelers and tool builders only non-standard ways of maintaining consistency between them. The libraries use a feature subsetting for this, but are not required to. For example, in Occurrences::HappensBefore, the earlier/laterOccurrence association end features subset the corresponding predecessors/successors features of the asssociated occurrence class by chaining through the other end feature:

    assoc all HappensBefore specializes HappensLink, Without {
      end feature earlierOccurrence: Occurrence[0..*] ... subsets laterOccurrence.predecessors;
      end feature laterOccurrence: Occurrence[0..*] ... subsets earlierOccurrence.successors; }
    
    abstract class Occurrence specializes Anything { ...
      feature predecessors: Occurrence[0..*] ... {...}
      feature successors: Occurrence[0..*] ... inverse of predecessors {...} }
    

    End features can be multiply subset, and do not identify which subsetting maintains consistency with the corresponding features in the associated classes, preventing tool builders from depending on the subsetting pattern to identify the corresponding features of the associated classifiers, even if the pattern were required.

  • Reported: KerML 1.0a1 — Wed, 26 Apr 2023 15:40 GMT
  • Updated: Thu, 11 Jul 2024 21:37 GMT

Number of association end feature values, semantics

  • Key: KERML_-17
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    The specification says that association "end" features have exactly one value each (see KERML-34 for spec excerpts and definition of terms), but this semantics is not math/modeled.

  • Reported: KerML 1.0a1 — Wed, 26 Apr 2023 14:23 GMT
  • Updated: Thu, 11 Jul 2024 21:37 GMT

End feature multiplicity textual notation

  • Key: KERML_-12
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    Background

    Consider the flowing simple structure:

    struct Car {
      feature carEngine : Engine[1];
      feature carWheels : Wheel[4];
      
      connector carDrive : Drive
        from carEngine to carWheels;
    }
    

    The feature multiplicities in this model require that each instance of Car have exactly one Engine and exactly four Wheels. The model also includes a usage of the following association:

    assoc Drive {
      end feature driveEngine : Engine[0..1];
      end feature driveWheel : Wheel[2..4];
    } 
    

    The Drive end multiplicities require that every Engine is connected to 2 to 4 Wheels, while every Wheel is connected to at most 1 Engine. But each instance of the association Drive is a link between a single engine and a single wheel. The multiplicities of the end features of Drive are thus interpreted differently than those of the features of Car (but consistently with how UML and SysML v1 interpret association end multiplicity). Rather than constraining the values of the end features themselves, the end multiplicities constrain the number of links allowed when the value at one end is held fixed: if a value is given for the driveEngine, then there must be two to four Drive links from that driveEngine to different Wheels; if a value is given for the driveWheel, then there must be zero or one instances between that driveWheel and an Engine.

    For example, consider the following usage of Car that explicitly binds all the Car features:

    feature myCar : Car {
      feature :>> carEngine = myEngine;
      feature :>> carWheels =
        (leftFrontWheel, rightFrontWheel, leftRearWheel, rightRearWheel);
      
      connector :>> carDrive =
        ( Drive(myEngine, leftRearWheel),
          Drive(myEngine, rightRearWheel)
        );
    }
    

    The connector ends of the connector carDrive inherit their end multiplicities from the ends of the association Drive. The above model explicitly binds the carDrive connector to two Drive values:

    1. a connection from myEngine to leftRearWheel

    2. a connection from myEngine to rightRearWheel

    This satisfies the multiplicity constraint for Drive, because the carEngine is linked to two Wheels (presuming leftRearWheel and rightRearWheel are different) and each carWheel is connected to at most one Engine.

    Concern

    While the semantic interpretation of the multiplicity of end features is different than that of non-end features, the same textual notation is used in both cases. This can be confusing, making it seem like, e.g., each instance of Drive has 0 or 1 driveEngine and 2 to 4 driveWheels, which would be the case for regular features but not for end features.

    Proposal

    Change the textual notation so that the multiplicity of an end feature is placed immediately after the end keyword, rather than in the usual place for a feature declaration. For example:

    assoc Drive {
      end [0..1] feature driveEngine : Engine;
      end [2..4] feature driveWheel : Wheel;
    }
    

    This would not require a change in the abstract syntax.

  • Reported: KerML 1.0a1 — Fri, 21 Apr 2023 23:14 GMT
  • Updated: Thu, 11 Jul 2024 21:37 GMT

Nary association end multiplicity, semantics

  • Key: KERML_-20
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clauses 7.4.5 (Associations) and 8.4.4.5.1 (Associations) say

    if an association end has a multiplicity specified other than 1..1, then this is interpreted as follows: For each association end, the multiplicity, ordering and uniqueness constraints specified for that end apply to each set of instance of the association that have the same (single) values for each of the other ends. For a binary association, this corresponds to the multiplicity resulting from "navigating" across the association given a value at one end of the association to the other end of the association.

    If an associationEnd has a declared multiplicity other than 1..1, then this shall be interpreted as follows: For an Association with N associationEnds, consider the i-th associationEnd ei. The multiplicity, ordering and uniqueness constraints specified for ei apply to each set of instances of the Association that have the same (singleton) values for each of the N-1 associationEnds other than ei.

    but this semantics is not math/modeled. In addition, the text above

    • does not seem to consider instances of associated classes that do not participate in any links, because only refers to instances of links. In the Product Selection example, the cart in red on the bottom left of the first slide violates the linkedProduct "end" multiplicity 1..*, but the text above would not detect it because it does not participate in any link.
    • Applies multiplicity, ordering and uniqueness to links (last sentence), which don't have these characteristics, rather than a feature with the values of ei from all the links.
  • Reported: KerML 1.0a1 — Wed, 26 Apr 2023 15:27 GMT
  • Updated: Thu, 11 Jul 2024 21:37 GMT
  • Attachments:

isReadOnly, semantics

  • Key: KERML_-4
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Read only features (Feature::isReadOnly=true) are described as

    Values of read only features on each instance of their domain are the same during the entire existence of that instance

    but this semantics is not model/mathed and depends on Kernel for instances existing in time.

  • Reported: KerML 1.0a1 — Thu, 13 Apr 2023 20:02 GMT
  • Updated: Wed, 10 Jul 2024 19:47 GMT

Restrict the functionality of recursive import

  • Key: KERML_-75
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The functionality of recursive importing is specified in the Namespace::visibleMemberships operation. If the isRecursive parameter of this operation is true, then the operation calls itself recursively on each Namespace that is a visible member (or any member, if isIncludeAll also is true) of the Namespace the operation was called on originally. This includes not only owned namespaces, but also those that are imported.

    Further, the visibleMemberships operation is redefined in Type to also include the visible inheritedMemberships of the Type. This nominally includes memberships inherited via implied Specializations as well as explicitly Specializations. This means that a recursive import will also potentially include a large number of names of standard library elements from Types in the recursive import graph, which is likely not what is intended by the modeler.

    So, as currently specified, recursive import unavoidably degrades the performance of any name resolution implementation, while including unintended functionality. To improve this, the following restrictions are recommended on the functionality of recursive import:

    1. Require recursive imports to be private.
    2. Only recurse on owned Namespaces.
    3. Do not included Memberships that are inherited via implied Specializations.
  • Reported: KerML 1.0b2 — Mon, 6 May 2024 04:20 GMT
  • Updated: Sat, 6 Jul 2024 15:43 GMT

Semantic constraint needed for result type of a "constructor" expression

  • Key: KERML_-52
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    In the KerML semantics, 8.4.4.9.4 Invocation Expressions, the semantic equivalent model for an InvocationExpression used as a "constructor" for a type T (i.e., T(...)) is shown as having its result parameter redefined with a FeatureTyping relationship to T. However, there is no semantic constraint in the abstract syntax to enforce this. Note that this typing is important, because it is to be expected that the result of a constructor is of the type being constructed.

  • Reported: KerML 1.0b1 — Fri, 1 Dec 2023 20:59 GMT
  • Updated: Sat, 6 Jul 2024 15:26 GMT

Confusing "Classes" with "Structures"

  • Key: KERML_-86
  • Status: open  
  • Source: Brandenburg University of Technology ( Gerd Wagner)
  • Summary:

    The sentence "Classes are required to (directly or indirectly) subclassify Object from the Objects library model, while Features typed by Classes must subset objects" should be changed to "Structures are required to (directly or indirectly) subclassify Object from the Objects library model, while Features typed by Structures must subset objects".

  • Reported: KerML 1.0b1 — Wed, 29 May 2024 14:58 GMT
  • Updated: Tue, 2 Jul 2024 11:39 GMT

Time and space life/slice/portion modeling patterns are missing

  • Key: KERML_-57
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clause 7.3.4.2 (Feature Declaration) and 8.3.3.3.3 (Feature) say

    Portion features are composite features where the values cannot exist without the whole, because they are the “same thing” as the whole. (For example, the portion of a person's life when they are a child cannot be added or removed from that person's life.)

    isPortion : Boolean
    Whether the values of this Feature are contained in the space and time of instances of the domain of the Feature and represent the same thing as those instances.

    and Clause 9.2.4.1 (Occurrences Overview) includes an extended description of time and space modeling in occurrences. But the specification does not explain how to model things (objects and performances) at specific times or places, versus over time or space. For example, cars are driven by one person at a time, but potentially many people over time. How should these multiplicities be specified? See other examples in comments on KERML-204.

  • Reported: KerML 1.0b1 — Mon, 1 Jan 2024 16:02 GMT
  • Updated: Wed, 5 Jun 2024 13:46 GMT
  • Attachments:

The OCL for isFeaturedWithin is still not correct

  • Key: KERML_-70
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The OCL for the operation Feature::isFeaturedWithin, as updated in the resolution to KERML-82, is still not correct. If a Feature has no featuringTypes, then it is implicitly "featured within" any Type. Therefore, isFeaturedWithin(type) should always return true in this case. Currently, though, the OCL specifies that it only returns true if type = null.

  • Reported: KerML 1.0b2 — Fri, 3 May 2024 18:48 GMT
  • Updated: Tue, 28 May 2024 00:12 GMT

relationship not defined

  • Key: KERML_-69
  • Status: open  
  • Source: Private ( Anders Reggestad)
  • Summary:

    Figure 4. Elements defines the relationship attribute, as well as several subsets depend on the same relationship though the attribute isn't anywhere to be found exept for in the figure 4.

  • Reported: KerML 1.0b2 — Fri, 19 Apr 2024 20:28 GMT
  • Updated: Tue, 28 May 2024 00:12 GMT

Invocation of a non-function behavior

  • Key: KERML_-67
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    In the Language Description, in 7.4.9.4 Base Expressions, in the fourth bullet for, it states that "A construction expression is an invocation expression in which the invocation target is a classifier that is not a function." However, in the Abstract Syntax, in 8.3.4.8.5 InvocationExpression, the constraint checkInvocationxpressionConstructorBindingConnector considers a constructor expression to be an InvocationExpression that "does not have an ownedTyping that is a Behavior or an ownedSubsetting of a Feature that is typed by a Behavior, then it must own a BindingConnector between itself and its result parameter." Further, in the Semantics, in 8.4.4.9.4 Invocation Expressions, it states

    An InvocationExpression may also have the form T(e1, e2, ...), where the invoked Type T is not a Function. If T is a Behavior other than a Function, then the InvocationExpression performs the Behavior, but has a null (empty) result value. If T is a Type that is not a Behavior, then the InvocationExpression acts as a constructor for an instance of the Type T.

    Now, invoking a behavior and having it return a null value doesn't really seem very useful. It would actually be more useful if, consistent with the language description, "invoking" a non-function behavior was considered to be a constructor expression, evaluating to a performance of that behavior. This would, in particular, allow out parameters to be referenced from the instantiated performance. For example:

    behavior B {in x; out y; out z;}
    feature y1 = B(1).y;
    feature b = B(2);
    feature y2 = b.y;
    feature z2 = b.z;
    
  • Reported: KerML 1.0b2 — Wed, 17 Apr 2024 22:17 GMT
  • Updated: Tue, 28 May 2024 00:12 GMT

isOrdered and isUnique are missing from the reflective abstract mapping

  • Key: KERML_-65
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The mapping given in 9.2.17 from the MOF abstract syntax model to the reflective KerML in abstract syntax model is missing instructions for what to do if a property is ordered or non-unique. Therefore, appropriate annotations for these are missing from the normative KerML.kerml file.

  • Reported: KerML 1.0b2 — Wed, 17 Apr 2024 21:12 GMT
  • Updated: Tue, 28 May 2024 00:12 GMT

FeatureIdentificationProduction is incorrect

  • Key: KERML_-63
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    In the KerML Specification, 8.2.4.3.1 Features, the production FeatureIdentification references the properties shortName and name. These should instead be declaredShortName and declaredName.

  • Reported: KerML 1.0b2 — Wed, 17 Apr 2024 20:36 GMT
  • Updated: Tue, 28 May 2024 00:12 GMT

Incorrect binding syntax in Feature Values Semantics

  • Key: KERML_-61
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    In 8.4.4.11 Feature Values Semantics, the following binding declaration appear in the second textual notation snippet:

    member binding f = e.result featured by T;

    and the fourth snippet:

    member binding f = e.result featured by that.startShot;

    These are both syntactically incorrect. The correct syntax is:

    member binding b featured by T of f=e.result;

    and

    member binding b featured by that.startShot of f=e.result;

  • Reported: KerML 1.0b2 — Wed, 17 Apr 2024 20:13 GMT
  • Updated: Tue, 28 May 2024 00:12 GMT

Impossible to specialize (redefine, subset) unnamed features in textual syntax

  • Key: KERML_-85
  • Status: open   Implementation work Blocked
  • Source: Budapest University of Technology and Economics ( Dr. Vince Molnar)
  • Summary:

    Since unnamed features cannot be referred to by name, there is no textual syntax to specialize them in a type subtyping the featuring type, even though the abstract syntax can express this relationship.

    Specialization is key in execution, where our current approach is to specialize and restrict user-defined types to a model that has a single (family of) interpretations, which is included in the set of original interpretatios (see Annex A). This involves redefining and subsetting the user-defined type's features.

    Based on the above, we can conclude that there is currently no way to describe an execution trace in the textual syntax for a model which contains unnamed elements.

  • Reported: KerML 1.0b2 — Mon, 27 May 2024 03:01 GMT
  • Updated: Mon, 27 May 2024 03:02 GMT

Some types not given any semantics

  • Key: KERML_-26
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    The Type metaclass is concrete (like all the metaclasses in the abstract syntax), making it it syntactically valid to create a Type that is not a Classifier or a Feature. However, Clause 8.4.3.1.2 (Core Semantics Mathematical Preliminaries) requires the set of Types in a model to be the union of the set of Classifiers and Features. This means instances of Type in a model that are not Classifiers or Features are syntactically valid, but not given semantics (it's not possible to tell if instances of such types are valid or not).

  • Reported: KerML 1.0a1 — Fri, 28 Apr 2023 20:16 GMT
  • Updated: Mon, 27 May 2024 02:33 GMT

Type::directionOf does not handle inheritence from feature chains

  • Key: KERML_-84
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    When a feature subsets a feature chain, the subsetting feature inherits features from the last feature in the subsetted feature chain. However, the OCL for the operation directionOf in 8.3.3.1.10 Type does not take this into account. It traverses upwards in the specialization and conjugation hierarchy without checking for feature chains.

    For example, consider the model

    behavior B {
        composite step s { in x; }
    }
    
    struct S {
        step b : B;
        feature f {
            feature c chains b.s;
            step s1 subsets c { out x1 redefines x; }
        }
    }
    

    In this model, the in parameter x is inheritable from b.s, so it can be redefined by x1 in step s1. However, according to the constraint validateRedefinitionDirectionConformance, one would expect that it would be an error to redefine x1 to be an out parameter, since x is an in parameter. But validateRedefinitionDirectionConformance uses the directionOf operation, which traverses the ownedSpecializations of feature c without considering its feature chaining. As a result, the directionOf parameter x relative to s1 is null rather than in, and the desired constraint does not apply.

  • Reported: KerML 1.0b2 — Wed, 22 May 2024 21:36 GMT
  • Updated: Wed, 22 May 2024 21:36 GMT

Editorial errors in constraints

  • Key: KERML_-72
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:
    1. In 8.3.3.3.10 Subsetting, in the description of validateSubsettingUniquenessConformance, change the second occurrence of subsettedFeature to subsettingFeature.
    2. In 8.3.4.5.3 Connector, in the OCL for checkConnectorBinaryObjectSpecialization, "AssocationStructure" should be "AssociationStructure".
    3. In 8.3.4.5.4 Succession, in the OCL for checkSuccessionSpecialization, "Occurences" should be "Occurrences".
  • Reported: KerML 1.0b2 — Fri, 3 May 2024 18:58 GMT
  • Updated: Wed, 22 May 2024 19:36 GMT

CollectExpression and SelectExpression should not reference BodyExpressionMember

  • Key: KERML_-83
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    In Concrete Syntax subclause 8.2.5.8.2 Primary Expressions, the productions for CollectExpression and SelectExpression refer to the production BodyExpressionMember, which is not actually defined in the concrete syntax grammar. These references should instead be to BodyArgumentMember, as also used in FunctionOperationExpression, and defined later in the same clause.

  • Reported: KerML 1.0b2 — Tue, 21 May 2024 15:50 GMT
  • Updated: Tue, 21 May 2024 15:50 GMT

deriveExpressionResult and deriveFunctionResult should be revised

  • Key: KERML_-68
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The properties Expression::result and Function::result subset parameter, which means they do not have to be ownedFeatures.

    The description of deriveExpressionResult states that

    If an Expression has a parameter owned via a ReturnParameterMembership, then that is its result parameter. Otherwise, its result parameter is the result parameter inherited from its function.

    As written, the OCL interprets this as meaning that the result parameter of an Expression is either owned by that Expression or inherited from the function of that Expression. However, this derivation does not allow for the possibility that an Expression might inherit its result parameter from a supertype Expression. It would seem to make more sense just to select the result as the parameter owned via a ReturnParameterMembership, whether directly owned or inherited (i.e., owned by a supertype) .

    Somewhat similarly, the description of the constraint deriveFunctionResult states that

    The result parameter of a Function is its parameter owned via a ReturnParameterMembership (if any).

    However, the OCL requires that the result parameter of a Function be owned by that Function and cannot be inherited. That seems to be more restrictive than was intended for this constraint.

  • Reported: KerML 1.0b2 — Mon, 22 Apr 2024 12:55 GMT
  • Updated: Fri, 10 May 2024 21:57 GMT

OCL for checkFeatureParameterRedefinition is wrong

  • Key: KERML_-59
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The description of the checkFeatureParameterRedefinition constraint is

    If a Feature is a parameter of an owningType that is a Behavior or Step, other than the result parameter (if any), then, for each direct supertype of its owningType that is also a Behavior or Step, it must redefine the parameter at the same position, if any.

    However, the OCL for the constraint does not exclude the result parameter as stated in the description.

  • Reported: KerML 1.0b2 — Wed, 17 Apr 2024 19:50 GMT
  • Updated: Mon, 22 Apr 2024 12:37 GMT

isEnd of the redefining feature must match isEnd of the redefined feature

  • Key: KERML_-1
  • Status: open  
  • Source: Dassault Systemes ( Mr. Tomas Juknevicius)
  • Summary:

    There is currently no validation rule/check constraint which enforces that when doing redefinitions, if redefined feature has isEnd=true, then redefining feature must also have isEnd=true;
    Which opens modelers to errors, e.g. in the SysML spec,
    ControlPerformances::DecisionPerformance::outgoingHBLink:: earlierOccurrence is not marked as "end" feature.

  • Reported: KerML 1.0b1 — Fri, 22 Mar 2024 19:18 GMT
  • Updated: Wed, 17 Apr 2024 21:18 GMT

checkFeatureParameterRedefinition fails for named-argument invocations

  • Key: KERML_-58
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    In 8.3.3.3.3 Feature, the constraint checkFeatureParameterRedefinition requires:

    If a Feature is a parameter of an owningType that is a Behavior or Step, other than the result parameter (if any), then, for each direct supertype of its owningType that is also a Behavior or Step, it must redefine the parameter at the same position, if any.

    However, in the textual BNF in 8.2.5.8.3 Base Expressions, a NamedArgumentList for an InvocationExpression is parsed with parameter redefinitions in the order of the argument list, not the original parameter list. Indeed, according to the description in 7.4.9.4 Base Expressions, named arguments may be "given in any order". But, if they are given in an order different than the original parameter order, this will violate checkFeatureParameterRedefinition. And then adding implied redefinitions to the InvocationExpression parameters, in the original parameter order, would potentially result each of the InvocationExpression parameters incorrectly redefining two different of the original parameters.

  • Reported: KerML 1.0b1 — Mon, 8 Jan 2024 04:35 GMT
  • Updated: Wed, 17 Apr 2024 20:15 GMT

checkFeatureParameterRedefinition fails for named-argument invocations

  • Key: KERML-308
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    In 8.3.3.3.3 Feature, the constraint checkFeatureParameterRedefinition requires:

    If a Feature is a parameter of an owningType that is a Behavior or Step, other than the result parameter (if any), then, for each direct supertype of its owningType that is also a Behavior or Step, it must redefine the parameter at the same position, if any.

    However, in the textual BNF in 8.2.5.8.3 Base Expressions, a NamedArgumentList for an InvocationExpression is parsed with parameter redefinitions in the order of the argument list, not the original parameter list. Indeed, according to the description in 7.4.9.4 Base Expressions, named arguments may be "given in any order". But, if they are given in an order different than the original parameter order, this will violate checkFeatureParameterRedefinition. And then adding implied redefinitions to the InvocationExpression parameters, in the original parameter order, would potentially result each of the InvocationExpression parameters incorrectly redefining two different of the original parameters.

  • Reported: KerML 1.0b1 — Mon, 8 Jan 2024 04:35 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Time and space life/slice/portion modeling patterns are missing

  • Key: KERML-306
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clause 7.3.4.2 (Feature Declaration) and 8.3.3.3.3 (Feature) say

    Portion features are composite features where the values cannot exist without the whole, because they are the “same thing” as the whole. (For example, the portion of a person's life when they are a child cannot be added or removed from that person's life.)

    isPortion : Boolean
    Whether the values of this Feature are contained in the space and time of instances of the domain of the Feature and represent the same thing as those instances.

    and Clause 9.2.4.1 (Occurrences Overview) includes an extended description of time and space modeling in occurrences. But the specification does not explain how to model things (objects and performances) at specific times or places, versus over time or space. For example, cars are driven by one person at a time, but potentially many people over time. How should these multiplicities be specified? See other examples in comments on KERML-204.

  • Reported: KerML 1.0b1 — Mon, 1 Jan 2024 16:02 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

isDerived, semantics

  • Key: KERML-246
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Derived features (Feature::isDerived=true) are described as

    Such a feature is typically expected to have a bound feature value expression that completely determines its value at all times.

    Whether the values of this Feature can always be computed from the values of other Feature.

    but this semantics is not model/mathed.

  • Reported: KerML 1.0b1 — Thu, 14 Dec 2023 15:32 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Space triggers missings

  • Key: KERML-283
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    KerML supports triggers on quantified time, but not quantified space, eg, that an object moves more than a specific distance, or comes within a specific distance of another, etc.

  • Reported: KerML 1.0b1 — Thu, 21 Dec 2023 17:05 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Discrepancy between documentation of Collections library in spec and textual notation file

  • Key: KERML-258
  • Status: open  
  • Source: DEKonsult ( Mr. Hans Peter de Koning)
  • Summary:

    The doc annotations of the datatypes in standard library Collections.kerml in machine readable document ad/23-02-05 are not aligned with the contents of subclause 9.3.3 of the KerML specification.

    The documentation content should be made identical. The text in the KerML specification should be leading when drafting a resolution for this issue.

  • Reported: KerML 1.0a1 — Wed, 20 Dec 2023 09:37 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Space triggers missings

  • Key: KERML_-56
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    KerML supports triggers on quantified time, but not quantified space, eg, that an object moves more than a specific distance, or comes within a specific distance of another, etc.

  • Reported: KerML 1.0b1 — Thu, 21 Dec 2023 17:05 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

isDerived, semantics

  • Key: KERML_-54
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Derived features (Feature::isDerived=true) are described as

    Such a feature is typically expected to have a bound feature value expression that completely determines its value at all times.

    Whether the values of this Feature can always be computed from the values of other Feature.

    but this semantics is not model/mathed.

  • Reported: KerML 1.0b1 — Thu, 14 Dec 2023 15:32 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Discrepancy between documentation of Collections library in spec and textual notation file

  • Key: KERML_-55
  • Status: open  
  • Source: DEKonsult ( Mr. Hans Peter de Koning)
  • Summary:

    The doc annotations of the datatypes in standard library Collections.kerml in machine readable document ad/23-02-05 are not aligned with the contents of subclause 9.3.3 of the KerML specification.

    The documentation content should be made identical. The text in the KerML specification should be leading when drafting a resolution for this issue.

  • Reported: KerML 1.0a1 — Wed, 20 Dec 2023 09:37 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Composite feature values can have more than one owner

  • Key: KERML-208
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    7.3.4.1 (Features Overview) says

    Values of a composite feature, on each instance of the feature's domain, cannot exist after the featuring instance ceases to exist.

    and 8.3.3.3.3 (Feature) says

    isComposite : Boolean
    Whether the Feature is a composite feature of its featuringType. If so, the values of the Feature cannot exist after its featuring instance no longer does.

    but the spec doesn't seem to say anywhere that the values cannot be values of any composite features on any other instance of the feature's domain ("single owner", "tree" property of composition), as typically expected.

  • Reported: KerML 1.0b1 — Tue, 7 Nov 2023 16:41 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

TimeOf::timeContinuityConstraint might be too restrictive

  • Key: KERML-233
  • Status: open  
  • Source: Budapest University of Technology and Economics ( Dr. Vince Molnar)
  • Summary:

    In Clocks.kerml, the TimeOf function defines the timeContinuityConstraint, which states that (endShots of) immediate predecessors of an occurrence (i.e., those connected via a HappensJustBefore) must get the same timestamp (timeInstant in the model) as the start shot of the occurrence:

    inv timeContinuityConstraint {
    	doc
    	/*
    	 * If one Occurrence happens immediately before another, then the TimeOf 
    	 * the end snapshot of the first Occurrence equals the TimeOf the second
    	 * Occurrence.
    	 */
    	
    	o.immediatePredecessors->forAll{in p : Occurrence; 
    		TimeOf(p.endShot, clock) == timeInstant
    	}
    }	
    

    Compare this to the documentation of HappensJustBefore, which states that "HappensJustBefore is HappensBefore asserting that there is no possibility of another occurrences[sic] happening in the time between the earlierOccurrence and laterOccurrence."

    Considering that the intent of the libraries is not to constrain the time model and the format of timestamps, I checked this against three widely-used time models.

    With continuous (dense) time, the current formulation of the timeContinuityConstraint might make sense, although it fails to capture that an infinite number of snapshots forming a HappensJustBefore chain may actually take non-zero time.

    With discrete time, where a timestamp may be treated as a sequence number, for example, an Integer, the invariant may be too restrictive, as HappensJustBefore could apply to two snapshots that have successive sequence numbers, but have no other occurrence in between them. In fact, in a discrete time model, HappensJustBefore with the current definition degrades to HappensWhile because there is no notion of ordering between events with the same timestamp.

    In super-dense time, where a clock is usually represented as a pair of a real value (timestamp) and an integer (sequence number to order events with the same timestamp), the invariant is again not very well defined because a pair with the same timestamp and smaller sequence number is generally considered to be (strictly) "less than".

    Overall, I think the difference between HappensBefore and HappensJustBefore cannot be captured in the TimeOf function, but should rather be enforced on the succession graph induced by these relations as specified in the documentation of HappensJustBefore (but not formalized, as far as I am aware), independent of the timestamps. This would imply that the invariant should be removed from the library.

    Alternatively, if the intent was to say there is no other possible value between the timestamp of the occurrence and that of its immediate predecessors (which degrades to the current definition with continuous time), the constraint could capture this better by asserting that there is no otherTimeInstant such that otherTimeInstant < timeInstant and TimeOf(p.endShot, clock) < otherTimeInstant. This would allow discrete clocks to assign successive timestamps to occurrences in a HappensJustBefore relation, forbid continuous clocks to assign different timestamps (as there is always another real number between any two), and force pairs in super-dense time to assign pairs with the same timestamp and either the same or successive sequence numbers.

  • Reported: KerML 1.0a1 — Sat, 25 Nov 2023 11:20 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Semantic constraint needed for result type of a "constructor" expression

  • Key: KERML-244
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    In the KerML semantics, 8.4.4.9.4 Invocation Expressions, the semantic equivalent model for an InvocationExpression used as a "constructor" for a type T (i.e., T(...)) is shown as having its result parameter redefined with a FeatureTyping relationship to T. However, there is no semantic constraint in the abstract syntax to enforce this. Note that this typing is important, because it is to be expected that the result of a constructor is of the type being constructed.

  • Reported: KerML 1.0b1 — Fri, 1 Dec 2023 20:59 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Some syntax in Core has time-dependent semantics

  • Key: KERML-211
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Some (abstract and textual) syntax in Core has (informal) semantics requiring time, such as Feature::isComposite, ::isReadOnly, ::isPortion, as well as ::direction and ::isDerived, see 7.3.4.2 (Feature Declaration) and 8.3.3.3.3 (Feature), but Core does not include a time model.

  • Reported: KerML 1.0a1 — Thu, 9 Nov 2023 14:13 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Annex A coverage

  • Key: KERML-207
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    The execution algorithm in Annex A should could more cases.

  • Reported: KerML 1.0b1 — Wed, 1 Nov 2023 20:08 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

TimeOf::timeContinuityConstraint might be too restrictive

  • Key: KERML_-51
  • Status: open  
  • Source: Budapest University of Technology and Economics ( Dr. Vince Molnar)
  • Summary:

    In Clocks.kerml, the TimeOf function defines the timeContinuityConstraint, which states that (endShots of) immediate predecessors of an occurrence (i.e., those connected via a HappensJustBefore) must get the same timestamp (timeInstant in the model) as the start shot of the occurrence:

    inv timeContinuityConstraint {
    	doc
    	/*
    	 * If one Occurrence happens immediately before another, then the TimeOf 
    	 * the end snapshot of the first Occurrence equals the TimeOf the second
    	 * Occurrence.
    	 */
    	
    	o.immediatePredecessors->forAll{in p : Occurrence; 
    		TimeOf(p.endShot, clock) == timeInstant
    	}
    }	
    

    Compare this to the documentation of HappensJustBefore, which states that "HappensJustBefore is HappensBefore asserting that there is no possibility of another occurrences[sic] happening in the time between the earlierOccurrence and laterOccurrence."

    Considering that the intent of the libraries is not to constrain the time model and the format of timestamps, I checked this against three widely-used time models.

    With continuous (dense) time, the current formulation of the timeContinuityConstraint might make sense, although it fails to capture that an infinite number of snapshots forming a HappensJustBefore chain may actually take non-zero time.

    With discrete time, where a timestamp may be treated as a sequence number, for example, an Integer, the invariant may be too restrictive, as HappensJustBefore could apply to two snapshots that have successive sequence numbers, but have no other occurrence in between them. In fact, in a discrete time model, HappensJustBefore with the current definition degrades to HappensWhile because there is no notion of ordering between events with the same timestamp.

    In super-dense time, where a clock is usually represented as a pair of a real value (timestamp) and an integer (sequence number to order events with the same timestamp), the invariant is again not very well defined because a pair with the same timestamp and smaller sequence number is generally considered to be (strictly) "less than".

    Overall, I think the difference between HappensBefore and HappensJustBefore cannot be captured in the TimeOf function, but should rather be enforced on the succession graph induced by these relations as specified in the documentation of HappensJustBefore (but not formalized, as far as I am aware), independent of the timestamps. This would imply that the invariant should be removed from the library.

    Alternatively, if the intent was to say there is no other possible value between the timestamp of the occurrence and that of its immediate predecessors (which degrades to the current definition with continuous time), the constraint could capture this better by asserting that there is no otherTimeInstant such that otherTimeInstant < timeInstant and TimeOf(p.endShot, clock) < otherTimeInstant. This would allow discrete clocks to assign successive timestamps to occurrences in a HappensJustBefore relation, forbid continuous clocks to assign different timestamps (as there is always another real number between any two), and force pairs in super-dense time to assign pairs with the same timestamp and either the same or successive sequence numbers.

  • Reported: KerML 1.0a1 — Sat, 25 Nov 2023 11:20 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Some syntax in Core has time-dependent semantics

  • Key: KERML_-50
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Some (abstract and textual) syntax in Core has (informal) semantics requiring time, such as Feature::isComposite, ::isReadOnly, ::isPortion, as well as ::direction and ::isDerived, see 7.3.4.2 (Feature Declaration) and 8.3.3.3.3 (Feature), but Core does not include a time model.

  • Reported: KerML 1.0a1 — Thu, 9 Nov 2023 14:13 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Composite feature values can have more than one owner

  • Key: KERML_-49
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    7.3.4.1 (Features Overview) says

    Values of a composite feature, on each instance of the feature's domain, cannot exist after the featuring instance ceases to exist.

    and 8.3.3.3.3 (Feature) says

    isComposite : Boolean
    Whether the Feature is a composite feature of its featuringType. If so, the values of the Feature cannot exist after its featuring instance no longer does.

    but the spec doesn't seem to say anywhere that the values cannot be values of any composite features on any other instance of the feature's domain ("single owner", "tree" property of composition), as typically expected.

  • Reported: KerML 1.0b1 — Tue, 7 Nov 2023 16:41 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Annex A coverage

  • Key: KERML_-48
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    The execution algorithm in Annex A should could more cases.

  • Reported: KerML 1.0b1 — Wed, 1 Nov 2023 20:08 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Serious limitation of textual concrete syntax as model interchange format

  • Key: KERML-205
  • Status: open  
  • Source: DEKonsult ( Mr. Hans Peter de Koning)
  • Summary:

    The specification in subclause 10.2 lists the textual concrete syntax as one format for model interchange.

    However, the textual concrete syntax does not include syntax for the elementId : UUID property of any element specified in such a model interchange. In general, this makes it impossible to derive the net semantic difference between model interchanges of a pair of revisions (or versions) of the same package represented in this format. The elementId identifiers are necessary to detect whether a change constitutes: (1) a newly created element, (2) an updated element (including a moved element), or (3) a deleted element. In general, it will only be possible to derive the net lexical difference. This limitation holds in particular for unnamed (i.e. anonymous) elements, as well as for elements with name and/or shortName changes.

    It is therefore debatable whether the textual concrete syntax may be designated as a proper model interchange format.

    This limitation of use of the textual concrete syntax as an interchange format should be explicitly addressed through one of the following:

    1. Add an explanation of the limitation in the specification.
    2. Add a facility in the textual concrete syntax to include representation of the elementId for any element. For usability reasons, implementations should provide a capability to show or hide the elementId snippets in the concrete textual notation editor widgets.
  • Reported: KerML 1.0b1 — Sat, 28 Oct 2023 14:22 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Ambiguity In Directionality InOut semantics

  • Key: KERML-168
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Literal Values
    inout
    "Values of the Feature on each instance are determined either as in or out directions, or both."
    In and out discuss 2 concepts of 'determination' of an instances value, and 'use' of an instances value
    Is 'inout' ambiguous as to the features determination and use completely or still constrained?
    Both 'in' and 'out' require opposite 'determination' than 'use', but can inout allow same 'determination' and 'use'?
    To be more clear, can an inout feature be 'determined' 'externally' and 'used' 'externally'?
    How is 'inout' different from not providing a directionality constraint?
    How does directionality work with specializations like subsetting/redefinition, should there be constraints?

  • Reported: KerML 1.0b1 — Sat, 16 Sep 2023 17:58 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Redefining features sometimes must respecify metaproperties even when they are the same as those of the redefined feature

  • Key: KERML-197
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    When redefining features, some metaproperties must be respecified even when they're intended to be the same as the redefined ones, while others don't. For example, feature type and multiplicity do not need to be respecified on a redefining feature when they are intended to be the same as the redefined feature, as I understand it, while direction does, even when it is intended to be the same as the redefined feature. Modelers must remember which feature metaproperties need to be respecified and which don't. The textual syntax would be easier to use if this were the same for all feature metaproperties, and more so if metaproperties could always be omitted in redefining features when they are intended to be the same as the redefined feature.

  • Reported: KerML 1.0b1 — Tue, 17 Oct 2023 19:02 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Read only, misleading keyword, metaproperty name

  • Key: KERML-206
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    The phrase "read only" is often enough taken to refer to features/properties that write actions (eg, FeatureWritePerformance) should not be applied to (see library errors in KERML-49, modeler misunderstandings in KERML-3 comments and UML constraint errors in UMLR-815), rather than having constant values, as intended.

  • Reported: KerML 1.0b1 — Mon, 30 Oct 2023 19:10 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Ambiguity In Directionality InOut semantics

  • Key: KERML_-44
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Literal Values
    inout
    "Values of the Feature on each instance are determined either as in or out directions, or both."
    In and out discuss 2 concepts of 'determination' of an instances value, and 'use' of an instances value
    Is 'inout' ambiguous as to the features determination and use completely or still constrained?
    Both 'in' and 'out' require opposite 'determination' than 'use', but can inout allow same 'determination' and 'use'?
    To be more clear, can an inout feature be 'determined' 'externally' and 'used' 'externally'?
    How is 'inout' different from not providing a directionality constraint?
    How does directionality work with specializations like subsetting/redefinition, should there be constraints?

  • Reported: KerML 1.0b1 — Sat, 16 Sep 2023 17:58 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Read only, misleading keyword, metaproperty name

  • Key: KERML_-47
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    The phrase "read only" is often enough taken to refer to features/properties that write actions (eg, FeatureWritePerformance) should not be applied to (see library errors in KERML-49, modeler misunderstandings in KERML-3 comments and UML constraint errors in UMLR-815), rather than having constant values, as intended.

  • Reported: KerML 1.0b1 — Mon, 30 Oct 2023 19:10 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Redefining features sometimes must respecify metaproperties even when they are the same as those of the redefined feature

  • Key: KERML_-45
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    When redefining features, some metaproperties must be respecified even when they're intended to be the same as the redefined ones, while others don't. For example, feature type and multiplicity do not need to be respecified on a redefining feature when they are intended to be the same as the redefined feature, as I understand it, while direction does, even when it is intended to be the same as the redefined feature. Modelers must remember which feature metaproperties need to be respecified and which don't. The textual syntax would be easier to use if this were the same for all feature metaproperties, and more so if metaproperties could always be omitted in redefining features when they are intended to be the same as the redefined feature.

  • Reported: KerML 1.0b1 — Tue, 17 Oct 2023 19:02 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Association end feature description missing simple example and equivalence to related types

  • Key: KERML-159
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clause 7.4.5 (Associations), first two paragraphs after the references at the top describes how to declare associations and use of end features, but the

    • only example of association end features is later when explaining the more advanced case of association specialization. The text references an earlier very brief description of end features in 7.3.4.2 (Feature Declaration), which points back to 7.4.5 for more information.
    • third paragraph (the one starting "An association is also a relationship between the types") describes related types, but does not mention these are same as the end feature types, as specified by the deriveAssociationRelatedType constraint in 8.3.4.4.2 (Association).

    Would helpful for 7.4.5 to include a simple example of association end features near the beginning where they are described, and to explain that related types are the same as end feature types.

  • Reported: KerML 1.0b1 — Thu, 7 Sep 2023 15:33 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Type::inheritedMemberships OCL is missing

  • Key: KERML-126
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clause 8.3.3.1.10 (Type), includes inheritedMemberships as an operation with a text description, but no OCL.

  • Reported: KerML 1.0a1 — Sun, 30 Jul 2023 14:08 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Root namespaces restricted to one single file

  • Key: KERML-163
  • Status: open  
  • Source: Robert Bosch GmbH ( Florian Beer)
  • Summary:

    Usecase: large corporation is working on a project, where also other suppliers deliver parts of the product architecture.

    To avoid naming collisions in such constellations, it makes sense to use hierarchical package structures. If everyone just uses plain structures, we have potential conflicts with a duplicate declaration of namespaces.
    As within large corporations hundreds of engineers can be working of one product class, which might be organized as namespaces, it makes sense to split the definition of multiple namespaces within the same parent namespace in different files to avoid merge conflicts

    Example

    package Vehicle{
       part engine : MyCorp::Automotive::Engine::SmallEngine;
       part gearFront : MyCorp::Automotive::Transmission::AT8Gear;
       part rearGear : SomeSupplier::Transmission::FancyGear;
    }
    

    Possible resolutions:
    1) allow duplicate definitions of namespaces and implicitly merges the resulting trees, dangerous as it could happen unintended
    2) allow to merge sub-trees of duplicate namespaces with a keyword
    2a) all except one namespace declaration require an addendum keyword, injection of elements possible which might expose private information
    2b) all namespaces must declare, that extension is possible

    example

    partial package CommonParent //declaration can be skipped, if nothing except namespace is declared
    package CommonParent::GroupA{
      //some declarations
    }
    package CommonParent::GroupB{
      //some more declarations
    }
    package CommonParent::IntegrationLayer{} //should work as no explicitly declared namespace is duplicated
    package CommonParent::GroupA::Backdoor {} //should generate an error as the explicitly declared namespace GroupA is duplicated
    
  • Reported: KerML 1.0b1 — Mon, 11 Sep 2023 17:55 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

TransitionPerformance modeling pattern more general than needed, not aligned with SysML::TransitionUsage

  • Key: KERML-157
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clause 9.2.10.1 (Transition Performances Overview) requires two connectors typed by associations, to constrain transitionLink and transitionLinkSource:

    The Succession constrained by a TransitionPerformance is specified by a Connector between the Succession and its transitionStep, a unique Step typed by TransitionPerformance or a specialization of it, of the same Behavior as the Succession. This connector is
    • typed by an Association defined to give a value to the transitionLink of TransitionPerformances,
    • has connector end multiplicity 0..1 on the Succession end and 1 on the TransitionPerformance Step end.

    The transitionStep above is also connected to the Succession's sourceFeature, because conditions on the Succession depend on each Occurrence of its sourceFeature separately, which TransitionPerformances identify as their transitionLinkSource. This connector is
    • typed by an Association defined to give a value to the transitionLinkSource of TransitionPerformances.
    • with connector end multiplicity 1 on both ends.

    but

    • succession could subset transitionStep.transitionLink (equivalent to a binding with optional multiplicity on succession end)
    • bind succession's sourceFeature and its transitionStep.transitionLinkSource (1 to 1 end multiplicities)

    giving the desired result without introducing new associations for each transitionStep. This would also align it with SysML's modeling pattern specified in TransitionUsage::checkTransitionUsageSuccessionBindingConnector and checkTransitionUsageSourceBindingConnector (after the latter is corrected as proposed in SYSML2-397).

  • Reported: KerML 1.0a1 — Fri, 25 Aug 2023 19:16 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Add validateSubsettingTypeConformance constraint

  • Key: KERML-127
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    There is currently no constraint that the typing of a subsetting feature conform to the typing of the subsetted feature. For example, the following is currently considered valid:

    classifier A;
    classifier B;
    
    feature x : A;
    feature y : B subsets x;
    

    even if there is no specialization relationship between A and B. Currently, what happens is that y picks up the additions the additional type A due to the subsetting. So the above declaration for y is essentially equivalent to

    feature y: B, A subsets x;
    

    Now, unless A and B are declared as disjoint, it is possible that there are instances classified by both A and B, so that this joint typing of y isn't vacuous. Nevertheless, it seems more useful, for static type checking, to presume disjointness and to disallow the above subsetting unless B can be statically determined to specialize A.

    This is relevant, in particular, for connectors, in which the related features are determined using reference subsetting. Consider the following:

    assoc C {
       end a: A;
       end b: B;
    }
    
    feature a1: A;
    feature b1: B;
    
    connector c: C from a ::> b1 to b ::> a1;
    

    Because of the above, this is currently allowed. But, as a result, this really seems to make the typing of association ends pretty much useless for connectors.

  • Reported: KerML 1.0b1 — Tue, 1 Aug 2023 15:32 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Association end feature description missing simple example and equivalence to related types

  • Key: KERML_-42
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clause 7.4.5 (Associations), first two paragraphs after the references at the top describes how to declare associations and use of end features, but the

    • only example of association end features is later when explaining the more advanced case of association specialization. The text references an earlier very brief description of end features in 7.3.4.2 (Feature Declaration), which points back to 7.4.5 for more information.
    • third paragraph (the one starting "An association is also a relationship between the types") describes related types, but does not mention these are same as the end feature types, as specified by the deriveAssociationRelatedType constraint in 8.3.4.4.2 (Association).

    Would helpful for 7.4.5 to include a simple example of association end features near the beginning where they are described, and to explain that related types are the same as end feature types.

  • Reported: KerML 1.0b1 — Thu, 7 Sep 2023 15:33 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Root namespaces restricted to one single file

  • Key: KERML_-43
  • Status: open  
  • Source: Robert Bosch GmbH ( Florian Beer)
  • Summary:

    Usecase: large corporation is working on a project, where also other suppliers deliver parts of the product architecture.

    To avoid naming collisions in such constellations, it makes sense to use hierarchical package structures. If everyone just uses plain structures, we have potential conflicts with a duplicate declaration of namespaces.
    As within large corporations hundreds of engineers can be working of one product class, which might be organized as namespaces, it makes sense to split the definition of multiple namespaces within the same parent namespace in different files to avoid merge conflicts

    Example

    package Vehicle{
       part engine : MyCorp::Automotive::Engine::SmallEngine;
       part gearFront : MyCorp::Automotive::Transmission::AT8Gear;
       part rearGear : SomeSupplier::Transmission::FancyGear;
    }
    

    Possible resolutions:
    1) allow duplicate definitions of namespaces and implicitly merges the resulting trees, dangerous as it could happen unintended
    2) allow to merge sub-trees of duplicate namespaces with a keyword
    2a) all except one namespace declaration require an addendum keyword, injection of elements possible which might expose private information
    2b) all namespaces must declare, that extension is possible

    example

    partial package CommonParent //declaration can be skipped, if nothing except namespace is declared
    package CommonParent::GroupA{
      //some declarations
    }
    package CommonParent::GroupB{
      //some more declarations
    }
    package CommonParent::IntegrationLayer{} //should work as no explicitly declared namespace is duplicated
    package CommonParent::GroupA::Backdoor {} //should generate an error as the explicitly declared namespace GroupA is duplicated
    
  • Reported: KerML 1.0b1 — Mon, 11 Sep 2023 17:55 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

TransitionPerformance modeling pattern more general than needed, not aligned with SysML::TransitionUsage

  • Key: KERML_-41
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clause 9.2.10.1 (Transition Performances Overview) requires two connectors typed by associations, to constrain transitionLink and transitionLinkSource:

    The Succession constrained by a TransitionPerformance is specified by a Connector between the Succession and its transitionStep, a unique Step typed by TransitionPerformance or a specialization of it, of the same Behavior as the Succession. This connector is
    • typed by an Association defined to give a value to the transitionLink of TransitionPerformances,
    • has connector end multiplicity 0..1 on the Succession end and 1 on the TransitionPerformance Step end.

    The transitionStep above is also connected to the Succession's sourceFeature, because conditions on the Succession depend on each Occurrence of its sourceFeature separately, which TransitionPerformances identify as their transitionLinkSource. This connector is
    • typed by an Association defined to give a value to the transitionLinkSource of TransitionPerformances.
    • with connector end multiplicity 1 on both ends.

    but

    • succession could subset transitionStep.transitionLink (equivalent to a binding with optional multiplicity on succession end)
    • bind succession's sourceFeature and its transitionStep.transitionLinkSource (1 to 1 end multiplicities)

    giving the desired result without introducing new associations for each transitionStep. This would also align it with SysML's modeling pattern specified in TransitionUsage::checkTransitionUsageSuccessionBindingConnector and checkTransitionUsageSourceBindingConnector (after the latter is corrected as proposed in SYSML2-397).

  • Reported: KerML 1.0a1 — Fri, 25 Aug 2023 19:16 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Add validateSubsettingTypeConformance constraint

  • Key: KERML_-40
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    There is currently no constraint that the typing of a subsetting feature conform to the typing of the subsetted feature. For example, the following is currently considered valid:

    classifier A;
    classifier B;
    
    feature x : A;
    feature y : B subsets x;
    

    even if there is no specialization relationship between A and B. Currently, what happens is that y picks up the additions the additional type A due to the subsetting. So the above declaration for y is essentially equivalent to

    feature y: B, A subsets x;
    

    Now, unless A and B are declared as disjoint, it is possible that there are instances classified by both A and B, so that this joint typing of y isn't vacuous. Nevertheless, it seems more useful, for static type checking, to presume disjointness and to disallow the above subsetting unless B can be statically determined to specialize A.

    This is relevant, in particular, for connectors, in which the related features are determined using reference subsetting. Consider the following:

    assoc C {
       end a: A;
       end b: B;
    }
    
    feature a1: A;
    feature b1: B;
    
    connector c: C from a ::> b1 to b ::> a1;
    

    Because of the above, this is currently allowed. But, as a result, this really seems to make the typing of association ends pretty much useless for connectors.

  • Reported: KerML 1.0b1 — Tue, 1 Aug 2023 15:32 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Type::inheritedMemberships OCL is missing

  • Key: KERML_-39
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clause 8.3.3.1.10 (Type), includes inheritedMemberships as an operation with a text description, but no OCL.

  • Reported: KerML 1.0a1 — Sun, 30 Jul 2023 14:08 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

validateAssociationStructureIntersection seems vacuous

  • Key: KERML-97
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The documentation for the validateAssociationStructureIntersection constraint is "If an Association is also a kind of Structure, then it must be an AssociationStructure." with the OCL

    oclIsKindOf(Structure) = oclIsKindOf(AssociationStructure)
    

    However, this is really a constraint on the abstract syntax, not user models. Since the current abstract syntax does not have any metaclass that is a subclass of both Structure and Association other than AssociationStructure, this constraint will always be true for every user model. (And, if the abstract syntax did include another subclass of both Structure and Association, then constraint would then be violated by every user model that used that construct!)

  • Reported: KerML 1.0b1 — Tue, 11 Jul 2023 20:11 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Inherited multiplicities, semantics

  • Key: KERML-124
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clause 8.4.4.12.1 (Multiplicities, Semantics) says

    The validateTypeOwnedMultiplicity constraint requires that a Type have at most one ownedMember that is a Multiplicity. If a Type has such an owned Multiplicity, then it is the typeWithMultiplicity of that Multiplicity. The value of the Multiplicity is then the cardinality of its typeWithMultiplicity and, therefore, the type (co-domain) of the Multiplicity restricts that cardinality.

    If a Type does not have an owned Multiplicity, but has ownedSpecializations, then its cardinality is constrained by the Multiplicities for all of the general Types of those ownedSpecializations (i.e., its direct supertypes). In practice, this means that the effective Multiplicity of the Type is the most restrictive Multiplicity of its direct supertypes.

    The above implies inherited multiplicities do not constrain cardinality of types that

    • own a Multiplicity
    • inherit them via unowned specializations

    while the (math) semantics for specialization and multiplicity says they do (rule 1 in 8.4.3.2, Types Semantics, and rule 5 in 8.4.3.4, Features Semantics, respectively).

  • Reported: KerML 1.0b1 — Sat, 29 Jul 2023 14:44 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Add derived property for targetFeature

  • Key: KERML-123
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    When a Feature has chainingFeatures, then it is sometimes useful to reference that last Feature in the chain in situations in which one would otherwise reference the owning Feature itself if there was no chain. For instance, in a graphical view, an edge with a chained Feature at an end will generally point to the last chainedFeature (possibly nested) rather than the chained Feature itself.

    Currently, this means that it is necessary to check for a feature f whether f.chainingFeature is non-empty and, if so, use f.chainingFeature->last() instead of f. It would be more convenient to have a derived property of Feature (called, say, targetFeature) that would do this automatically, that is, be derived as

    targetFeature = if chainingFeature.isEmpty() then self else chainingFeature->last() end if
    
  • Reported: KerML 1.0b1 — Sun, 16 Jul 2023 20:19 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

FeatureMembership owningType attribute ambiguity

  • Key: KERML-116
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Attributes
    /owningType : Type {subsets type, redefines membershipOwningNamespace, type}

    It is not "immediately" clear which 'type' metaproperty of which metaclass is the subsetted one, and which one is the redefined one. I think the semantics is meant to be that the redefines is for Featuring.type while the subsets is for the unnamed Association with the Type.featureMembership at it's other end.

    KERML-22 already requests to name the Association, it should probably define the derivation rule for it's owned derived /type metaproperty... probably subsets membershipNamespace.. it may actually redefine membershipNamespace since only types can own FeatureMemberships

  • Reported: KerML 1.0b1 — Mon, 10 Jul 2023 00:35 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

KerML Libraries' elements shall have an elementId defined

  • Key: KERML-121
  • Status: open  
  • Source: Airbus Group ( Mr. Yves Bernard)
  • Summary:

    The way KerML libraries are provided relies on textual notation files on which element declarations do not include the specification of their elementId property.

    As consequence, if the elementId is actually generated by the tool, as written in the KerML specification (p226), it is very likely to have a different value from one computer to another and even from one loading to another on the same computer.

    Hence, it is impossible to make sure it will "not change during the lifetime of the Element", as required by in the same paragraph of that specification.

    Note: a similar issue will be raised on SysMLv2

  • Reported: KerML 1.0a1 — Thu, 13 Jul 2023 06:48 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

KerML Libraries' elements shall have an elementId defined

  • Key: KERML_-36
  • Status: open  
  • Source: Airbus Group ( Mr. Yves Bernard)
  • Summary:

    The way KerML libraries are provided relies on textual notation files on which element declarations do not include the specification of their elementId property.

    As consequence, if the elementId is actually generated by the tool, as written in the KerML specification (p226), it is very likely to have a different value from one computer to another and even from one loading to another on the same computer.

    Hence, it is impossible to make sure it will "not change during the lifetime of the Element", as required by in the same paragraph of that specification.

    Note: a similar issue will be raised on SysMLv2

  • Reported: KerML 1.0a1 — Thu, 13 Jul 2023 06:48 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

FeatureMembership owningType attribute ambiguity

  • Key: KERML_-35
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Attributes
    /owningType : Type {subsets type, redefines membershipOwningNamespace, type}

    It is not "immediately" clear which 'type' metaproperty of which metaclass is the subsetted one, and which one is the redefined one. I think the semantics is meant to be that the redefines is for Featuring.type while the subsets is for the unnamed Association with the Type.featureMembership at it's other end.

    KERML-22 already requests to name the Association, it should probably define the derivation rule for it's owned derived /type metaproperty... probably subsets membershipNamespace.. it may actually redefine membershipNamespace since only types can own FeatureMemberships

  • Reported: KerML 1.0b1 — Mon, 10 Jul 2023 00:35 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Inherited multiplicities, semantics

  • Key: KERML_-38
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clause 8.4.4.12.1 (Multiplicities, Semantics) says

    The validateTypeOwnedMultiplicity constraint requires that a Type have at most one ownedMember that is a Multiplicity. If a Type has such an owned Multiplicity, then it is the typeWithMultiplicity of that Multiplicity. The value of the Multiplicity is then the cardinality of its typeWithMultiplicity and, therefore, the type (co-domain) of the Multiplicity restricts that cardinality.

    If a Type does not have an owned Multiplicity, but has ownedSpecializations, then its cardinality is constrained by the Multiplicities for all of the general Types of those ownedSpecializations (i.e., its direct supertypes). In practice, this means that the effective Multiplicity of the Type is the most restrictive Multiplicity of its direct supertypes.

    The above implies inherited multiplicities do not constrain cardinality of types that

    • own a Multiplicity
    • inherit them via unowned specializations

    while the (math) semantics for specialization and multiplicity says they do (rule 1 in 8.4.3.2, Types Semantics, and rule 5 in 8.4.3.4, Features Semantics, respectively).

  • Reported: KerML 1.0b1 — Sat, 29 Jul 2023 14:44 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

validateAssociationStructureIntersection seems vacuous

  • Key: KERML_-34
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The documentation for the validateAssociationStructureIntersection constraint is "If an Association is also a kind of Structure, then it must be an AssociationStructure." with the OCL

    oclIsKindOf(Structure) = oclIsKindOf(AssociationStructure)
    

    However, this is really a constraint on the abstract syntax, not user models. Since the current abstract syntax does not have any metaclass that is a subclass of both Structure and Association other than AssociationStructure, this constraint will always be true for every user model. (And, if the abstract syntax did include another subclass of both Structure and Association, then constraint would then be violated by every user model that used that construct!)

  • Reported: KerML 1.0b1 — Tue, 11 Jul 2023 20:11 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Association ends can have more than one type

  • Key: KERML-76
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    In general, Feature::type can have more than one value, and there is no restriction on this for end Features. The Association::relatedType property is derived as all the types of all the associationEnds of the Association. However, Association::sourceType is derived to be just the first relatedType. But consider the following Association:

    assoc A {
        end feature x : X1, X2;
        end feature y : Y1, Y2;
    }
    

    Even though this is a binary Association (it has exactly two ends), it has four relatedTypes: X1, X2, Y1 and Y2. As a binary Association, though, it (implicitly) specializes the library Association BinaryAssociation, with the first end redefining the source and the second end redefining the target. However, with the current derivation, the sourceType of A will be only X1, and the targetTypes will be X2, Y1 and Y2 – even though X2 is a type of the source end.

  • Reported: KerML 1.0a1 — Wed, 10 May 2023 22:15 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Default for the first operand of a classification expression

  • Key: KERML-93
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    In 7.4.9.2 OperatorExpressions, in the bullet for "Classification expressions", it states:

    The classification operators may also be used without a first operand, in which case the first operand is implicitly Anything::self (see 9.2.2.2.1). This is useful, in particular, when used as a test within an element filter condition expression (see 7.4.14).

    In the concrete syntax, in 8.2.5.8.1 Operator Expressions, the production for ClassificationExpression does, indeed, allow the first operand to be optional. However, there is nothing stated there (or anywhere else in normative Clause 8) about the default for the first operand being Anything::self if it is not given explicitly, as stated in 7.4.9.2.

  • Reported: KerML 1.0a1 — Mon, 3 Jul 2023 23:00 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Invariants only hold when evaluated

  • Key: KERML-63
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clauses 7.4.8.1 (Functions Overview) and 8.4.4.8.2 (Expressions and Invariants) say

    An invariant, though, is a boolean expression that must always evaluate to either true at all times or false at all times. By default, an invariant is asserted to always evaluate to true, while a negated invariant is asserted to always evaluate to false.

    Expressions are kinds of Steps. The checkExpressionSpecialization constraint requires that Expressions specialize the base Expression Performances::evaluations (see 9.2.6.2.3), which is a specialization of Performances::performances.

    the checkInvariantSpecialization constraint requires that Invariants specialize either the BooleanExpression Performances::trueEvaluations (see 9.2.6.2.2) or, if the Invariant is negated, the BooleanExpression Performances::falseEvaluations (see 9.2.6.2.2), both of which are specializations of Performances::booleanEvaluations.

    where the Performance library defines

    abstract expr trueEvaluations subsets booleanEvaluations { true }
    
    abstract expr falseEvaluations subsets booleanEvaluations { false }
    

    but do not require models to specify when invariant expressions are evaluated, which are the only times the results are required to be true/false. The conditions they test for might be present only when the invariants happen to be evaluated (see KERML-58 for more about this).

  • Reported: KerML 1.0a1 — Fri, 5 May 2023 13:55 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Some package-level features are mandatory

  • Key: KERML-57
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    [From Vince Molnar] Package-level features do not give featuring types, and some have lower multiplicity greater than zero, meaning everything in the universe (instances of Anything), including every data value, is required to give at least that number of values to them (see KERML-56). For example, the libraries include:

    Clocks::universalClock[1] {...}
    Observation::defaultMonitor[1] : ChangeMonitor[1] {...}
    SpatialFrames::defaultFrame : SpatialFrame[1] {...}
    

    Might be others. This one

    Occurrences::earlierFirstIncomingTransferSort: IncomingTransferSort{... }
    

    does not give a multiplicity, I couldn't find what this means (even for expressions), tho this particular feature is supposed to have exactly one value.

  • Reported: KerML 1.0a1 — Mon, 1 May 2023 15:32 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Feature values do not specify when their expressions are evaluated

  • Key: KERML-58
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clause 8.3.4.10.2 (FeatureValue) and 8.4.4.11 (Feature Values Semantics) say

    A FeatureValue is a Membership that identifies a particular member Expression that provides the value of the Feature that owns the FeatureValue.

    A FeatureValue is a kind of OwningMembership between a Feature and an Expression.

    but does not require the model to specify when the expression is evaluated. Expressions (as steps) owned by some features are required to happen (be evaluated) during instances of the featuring types (domain) of that feature (see KERML-11), which might be too loose for some applications, while those owned other features are unconstrained, for example, their values could be the results of an expression evaluated before or after the instance of domain types exists. The results could vary over time if the expression reads values of other features. This seems to apply to all the combinations of default/initial feature values.

  • Reported: KerML 1.0a1 — Mon, 1 May 2023 19:47 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Some package-level features are mandatory

  • Key: KERML_-29
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    [From Vince Molnar] Package-level features do not give featuring types, and some have lower multiplicity greater than zero, meaning everything in the universe (instances of Anything), including every data value, is required to give at least that number of values to them (see KERML-56). For example, the libraries include:

    Clocks::universalClock[1] {...}
    Observation::defaultMonitor[1] : ChangeMonitor[1] {...}
    SpatialFrames::defaultFrame : SpatialFrame[1] {...}
    

    Might be others. This one

    Occurrences::earlierFirstIncomingTransferSort: IncomingTransferSort{... }
    

    does not give a multiplicity, I couldn't find what this means (even for expressions), tho this particular feature is supposed to have exactly one value.

  • Reported: KerML 1.0a1 — Mon, 1 May 2023 15:32 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Association ends can have more than one type

  • Key: KERML_-32
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    In general, Feature::type can have more than one value, and there is no restriction on this for end Features. The Association::relatedType property is derived as all the types of all the associationEnds of the Association. However, Association::sourceType is derived to be just the first relatedType. But consider the following Association:

    assoc A {
        end feature x : X1, X2;
        end feature y : Y1, Y2;
    }
    

    Even though this is a binary Association (it has exactly two ends), it has four relatedTypes: X1, X2, Y1 and Y2. As a binary Association, though, it (implicitly) specializes the library Association BinaryAssociation, with the first end redefining the source and the second end redefining the target. However, with the current derivation, the sourceType of A will be only X1, and the targetTypes will be X2, Y1 and Y2 – even though X2 is a type of the source end.

  • Reported: KerML 1.0a1 — Wed, 10 May 2023 22:15 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Feature values do not specify when their expressions are evaluated

  • Key: KERML_-30
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clause 8.3.4.10.2 (FeatureValue) and 8.4.4.11 (Feature Values Semantics) say

    A FeatureValue is a Membership that identifies a particular member Expression that provides the value of the Feature that owns the FeatureValue.

    A FeatureValue is a kind of OwningMembership between a Feature and an Expression.

    but does not require the model to specify when the expression is evaluated. Expressions (as steps) owned by some features are required to happen (be evaluated) during instances of the featuring types (domain) of that feature (see KERML-11), which might be too loose for some applications, while those owned other features are unconstrained, for example, their values could be the results of an expression evaluated before or after the instance of domain types exists. The results could vary over time if the expression reads values of other features. This seems to apply to all the combinations of default/initial feature values.

  • Reported: KerML 1.0a1 — Mon, 1 May 2023 19:47 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Invariants only hold when evaluated

  • Key: KERML_-31
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clauses 7.4.8.1 (Functions Overview) and 8.4.4.8.2 (Expressions and Invariants) say

    An invariant, though, is a boolean expression that must always evaluate to either true at all times or false at all times. By default, an invariant is asserted to always evaluate to true, while a negated invariant is asserted to always evaluate to false.

    Expressions are kinds of Steps. The checkExpressionSpecialization constraint requires that Expressions specialize the base Expression Performances::evaluations (see 9.2.6.2.3), which is a specialization of Performances::performances.

    the checkInvariantSpecialization constraint requires that Invariants specialize either the BooleanExpression Performances::trueEvaluations (see 9.2.6.2.2) or, if the Invariant is negated, the BooleanExpression Performances::falseEvaluations (see 9.2.6.2.2), both of which are specializations of Performances::booleanEvaluations.

    where the Performance library defines

    abstract expr trueEvaluations subsets booleanEvaluations { true }
    
    abstract expr falseEvaluations subsets booleanEvaluations { false }
    

    but do not require models to specify when invariant expressions are evaluated, which are the only times the results are required to be true/false. The conditions they test for might be present only when the invariants happen to be evaluated (see KERML-58 for more about this).

  • Reported: KerML 1.0a1 — Fri, 5 May 2023 13:55 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Default for the first operand of a classification expression

  • Key: KERML_-33
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    In 7.4.9.2 OperatorExpressions, in the bullet for "Classification expressions", it states:

    The classification operators may also be used without a first operand, in which case the first operand is implicitly Anything::self (see 9.2.2.2.1). This is useful, in particular, when used as a test within an element filter condition expression (see 7.4.14).

    In the concrete syntax, in 8.2.5.8.1 Operator Expressions, the production for ClassificationExpression does, indeed, allow the first operand to be optional. However, there is nothing stated there (or anywhere else in normative Clause 8) about the default for the first operand being Anything::self if it is not given explicitly, as stated in 7.4.9.2.

  • Reported: KerML 1.0a1 — Mon, 3 Jul 2023 23:00 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Some types not given any semantics

  • Key: KERML-52
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    The Type metaclass is concrete (like all the metaclasses in the abstract syntax), making it it syntactically valid to create a Type that is not a Classifier or a Feature. However, Clause 8.4.3.1.2 (Core Semantics Mathematical Preliminaries) requires the set of Types in a model to be the union of the set of Classifiers and Features. This means instances of Type in a model that are not Classifiers or Features are syntactically valid, but not given semantics (it's not possible to tell if instances of such types are valid or not).

  • Reported: KerML 1.0a1 — Fri, 28 Apr 2023 20:16 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

XMI and JSON for model libraries

  • Key: KERML-51
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Project interchange files (.kpar) were submitted for all model libraries. However, in all cases, these archives only included textual notation model interchange files (.kerml). There should also be normative model library project interchange files in which the models are formatted in XMI and JSON.

  • Reported: KerML 1.0a1 — Fri, 28 Apr 2023 19:51 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Connector ends cannot give smaller lower multiplicity than their association ends

  • Key: KERML-55
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clause 8.4.4.6.1 (Connectors, Semantics) says (see KERML-34 for term definitions)

    the checkFeatureEndRedefinition constraint requires that the connectorEnds of a Connector redefine the associationEnds of its typing Associations. As a result, a Connector typed by an N-ary Association is essentially required to have the form (with implicit relatiojnships included):

    connector a : A subsets Links::links {
    end feature e1 redefines A::e1 references f1;
    end feature e2 redefines A::e2 references f2;
    ...
    end feature eN redefines A::eN references fN; }
    

    where e1, e2, ..., eN are the names of associationEnds of the Association A, in the order they are defined in A, and the f1, f2, ..., fN are the relatedFeatures of the Connector. Multiplicities declared for connectorEnds have the same special semantics as for associationEnds (see 8.4.4.5).

    while 8.3.3.3.8 (Redefinition), under Description (and similar wording in 7.3.4.5 Redefinition) says

    Redefinition is a kind of Subsetting that requires the redefinedFeature and the redefiningFeature to have the same values (on each instance of the domain of the redefiningFeature). This means any restrictions on the redefiningFeature, such as type or multiplicity, also apply to the redefinedFeature (on each instance of the domain of the redefiningFeature), and vice versa.

    preventing connector ends from giving a smaller lower multiplicity of the corresponding end of their (association) type. For example, people have exactly two parents, but a connector typed by that association might need to specify a [0..2] multiplicity on the parent end to reflect a particular purpose of identifying parents by that connector (such as "lives with").

    This restriction is mentioned informally in Clause 8.4.4.6.2 (Binding Connectors):

    Since both associationEnds of SelfLink have multiplicity 1..1, both connectorEnds of a BindingConnector do also.

    even though some bindings in the libraries have optional connector end multiplicities (see KERML-27).

  • Reported: KerML 1.0a1 — Sun, 30 Apr 2023 15:41 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Machine readable project interchange file(s) for language description examples

  • Key: KERML-53
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    Clause 7 Language Description includes a large number of example models and snippets, in textual and graphical notation. However, no machine-readable interchange file was submitted for these models. Project interchange files should be provided for them, including textual notation, XMI and JSON versions.

  • Reported: KerML 1.0a1 — Sat, 29 Apr 2023 20:42 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Machine readable project interchange file(s) for language description examples

  • Key: KERML_-27
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    Clause 7 Language Description includes a large number of example models and snippets, in textual and graphical notation. However, no machine-readable interchange file was submitted for these models. Project interchange files should be provided for them, including textual notation, XMI and JSON versions.

  • Reported: KerML 1.0a1 — Sat, 29 Apr 2023 20:42 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Connector ends cannot give smaller lower multiplicity than their association ends

  • Key: KERML_-28
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clause 8.4.4.6.1 (Connectors, Semantics) says (see KERML-34 for term definitions)

    the checkFeatureEndRedefinition constraint requires that the connectorEnds of a Connector redefine the associationEnds of its typing Associations. As a result, a Connector typed by an N-ary Association is essentially required to have the form (with implicit relatiojnships included):

    connector a : A subsets Links::links {
    end feature e1 redefines A::e1 references f1;
    end feature e2 redefines A::e2 references f2;
    ...
    end feature eN redefines A::eN references fN; }
    

    where e1, e2, ..., eN are the names of associationEnds of the Association A, in the order they are defined in A, and the f1, f2, ..., fN are the relatedFeatures of the Connector. Multiplicities declared for connectorEnds have the same special semantics as for associationEnds (see 8.4.4.5).

    while 8.3.3.3.8 (Redefinition), under Description (and similar wording in 7.3.4.5 Redefinition) says

    Redefinition is a kind of Subsetting that requires the redefinedFeature and the redefiningFeature to have the same values (on each instance of the domain of the redefiningFeature). This means any restrictions on the redefiningFeature, such as type or multiplicity, also apply to the redefinedFeature (on each instance of the domain of the redefiningFeature), and vice versa.

    preventing connector ends from giving a smaller lower multiplicity of the corresponding end of their (association) type. For example, people have exactly two parents, but a connector typed by that association might need to specify a [0..2] multiplicity on the parent end to reflect a particular purpose of identifying parents by that connector (such as "lives with").

    This restriction is mentioned informally in Clause 8.4.4.6.2 (Binding Connectors):

    Since both associationEnds of SelfLink have multiplicity 1..1, both connectorEnds of a BindingConnector do also.

    even though some bindings in the libraries have optional connector end multiplicities (see KERML-27).

  • Reported: KerML 1.0a1 — Sun, 30 Apr 2023 15:41 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Nary association end multiplicity, semantics

  • Key: KERML-40
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clauses 7.4.5 (Associations) and 8.4.4.5.1 (Associations) say

    if an association end has a multiplicity specified other than 1..1, then this is interpreted as follows: For each association end, the multiplicity, ordering and uniqueness constraints specified for that end apply to each set of instance of the association that have the same (single) values for each of the other ends. For a binary association, this corresponds to the multiplicity resulting from "navigating" across the association given a value at one end of the association to the other end of the association.

    If an associationEnd has a declared multiplicity other than 1..1, then this shall be interpreted as follows: For an Association with N associationEnds, consider the i-th associationEnd ei. The multiplicity, ordering and uniqueness constraints specified for ei apply to each set of instances of the Association that have the same (singleton) values for each of the N-1 associationEnds other than ei.

    but this semantics is not math/modeled. In addition, the text above

    • does not seem to consider instances of associated classes that do not participate in any links, because only refers to instances of links. In the Product Selection example, the cart in red on the bottom left of the first slide violates the linkedProduct "end" multiplicity 1..*, but the text above would not detect it because it does not participate in any link.
    • Applies multiplicity, ordering and uniqueness to links (last sentence), which don't have these characteristics, rather than a feature with the values of ei from all the links.
  • Reported: KerML 1.0a1 — Wed, 26 Apr 2023 15:27 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT
  • Attachments:

Association end features are not necessarily consistent with corresponding features of associated classifiers

  • Key: KERML-41
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    The textual and abstract syntaxes (at least) for association end features do not relate to the corresponding ones in the associated classes (association ends in SysML1.x/UML sense, see KERML-34 for term definitions), leaving modelers and tool builders only non-standard ways of maintaining consistency between them. The libraries use a feature subsetting for this, but are not required to. For example, in Occurrences::HappensBefore, the earlier/laterOccurrence association end features subset the corresponding predecessors/successors features of the asssociated occurrence class by chaining through the other end feature:

    assoc all HappensBefore specializes HappensLink, Without {
      end feature earlierOccurrence: Occurrence[0..*] ... subsets laterOccurrence.predecessors;
      end feature laterOccurrence: Occurrence[0..*] ... subsets earlierOccurrence.successors; }
    
    abstract class Occurrence specializes Anything { ...
      feature predecessors: Occurrence[0..*] ... {...}
      feature successors: Occurrence[0..*] ... inverse of predecessors {...} }
    

    End features can be multiply subset, and do not identify which subsetting maintains consistency with the corresponding features in the associated classes, preventing tool builders from depending on the subsetting pattern to identify the corresponding features of the associated classifiers, even if the pattern were required.

  • Reported: KerML 1.0a1 — Wed, 26 Apr 2023 15:40 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Sufficiency missing for some library types

  • Key: KERML-47
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Some library types might be intended to be sufficient. For example, in Occurrences::Occurrence, the values of

    feature spaceTimeCoincidentOccurrences: Occurrence[1..*] subsets timeCoincidentOccurrences, spaceEnclosedOccurrences ... { ...
      feature redefines thatOccurrence subsets largerSpace;
      feature redefines thisOccurrence subsets smallerSpace;
      connector :InsideOf from largerSpace references thatOccurrence [1]
                          to smallerSpace references thisOccurrence [1]; }
    

    presumably should include all timeCoincident/spaceEnclosedOccurrences that meet the condition given by the connector, but the feature is not marked as sufficient. Might be others like this.

  • Reported: KerML 1.0a1 — Fri, 28 Apr 2023 14:50 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Conditions missing for some sufficient library types

  • Key: KERML-48
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Some library types are sufficient, but do give give any conditions. For example, in Occurrences::Occurrence::

    portion feature all portions: Occurrence[1..*] subsets spaceTimeEnclosedOccurrences { ... }
    

    only has text documentation between the curly braces, leaving sufficiency to mean that portions and spaceTimeEnclosedOccurrences are equivalent. Might be others like this.

  • Reported: KerML 1.0a1 — Fri, 28 Apr 2023 14:56 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Performance & Object self redefinition missing in specification document

  • Key: KERML-50
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Performances::Performance and Objects::Object redefine self in the libraries, but Clauses 9.2.6.2.13 (Performance) and 9.2.5.2.7 (Object) are missing entries for these. Might be other self redefinitions missing also.

  • Reported: KerML 1.0a1 — Fri, 28 Apr 2023 19:47 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Performance & Object self redefinition missing in specification document

  • Key: KERML_-24
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Performances::Performance and Objects::Object redefine self in the libraries, but Clauses 9.2.6.2.13 (Performance) and 9.2.5.2.7 (Object) are missing entries for these. Might be other self redefinitions missing also.

  • Reported: KerML 1.0a1 — Fri, 28 Apr 2023 19:47 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Sufficiency missing for some library types

  • Key: KERML_-22
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Some library types might be intended to be sufficient. For example, in Occurrences::Occurrence, the values of

    feature spaceTimeCoincidentOccurrences: Occurrence[1..*] subsets timeCoincidentOccurrences, spaceEnclosedOccurrences ... { ...
      feature redefines thatOccurrence subsets largerSpace;
      feature redefines thisOccurrence subsets smallerSpace;
      connector :InsideOf from largerSpace references thatOccurrence [1]
                          to smallerSpace references thisOccurrence [1]; }
    

    presumably should include all timeCoincident/spaceEnclosedOccurrences that meet the condition given by the connector, but the feature is not marked as sufficient. Might be others like this.

  • Reported: KerML 1.0a1 — Fri, 28 Apr 2023 14:50 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Conditions missing for some sufficient library types

  • Key: KERML_-23
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Some library types are sufficient, but do give give any conditions. For example, in Occurrences::Occurrence::

    portion feature all portions: Occurrence[1..*] subsets spaceTimeEnclosedOccurrences { ... }
    

    only has text documentation between the curly braces, leaving sufficiency to mean that portions and spaceTimeEnclosedOccurrences are equivalent. Might be others like this.

  • Reported: KerML 1.0a1 — Fri, 28 Apr 2023 14:56 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Context-dependent meanings for feature multiplicity, ordering, and uniqueness

  • Key: KERML-37
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    The specification gives Feature::multiplicity, ordering, and uniqueness very different meanings for what it calls "end" features (see KERML-34 for definition of terms) than other features. This requires modelers and tool builders to create special cases in their minds and implementations to accommodate it. It also prevents

    • connector ends from giving smaller lower multiplicity than their association ends (see KERML-55)
    • participant features from specifying how many values they have (see KERML-35)
    • multiplicities from being uniquely specified (see KERML-36).

    Normally feature multiplicity restricts the number of values of a feature, but for association "end" features it restricts the number of values of the corresponding features of associated classifiers (association ends in SysML1.x/UML sense,(see KERML-34 for definition of terms) about terms), see excepts below. For example, in the Product Selection example, the info feature of association Selection has the usual semantics for multiplicity, but the "end" features linkedCart an linkedProduct do not. The same comments apply to end ordering and uniqueness.

    Clause 7.4.5 (Associations) says

    The semantics of multiplicity is different for end features from that for non-end features (as described in 7.3.4.2). The end features of an association determine the participants in the links that are instances of the association and, as such, effectively have multiplicity of "1" relative to the association. But, if an association end has a multiplicity specified other than 1..1, then this is interpreted as follows: For each association end, the multiplicity, ordering and uniqueness constraints specified for that end apply to each set of instance of the association that have the same (single) values for each of the other ends. For a binary association, this corresponds to the multiplicity resulting from "navigating" across the association given a value at one end of the association to the other end of the association.

    Clause 8.4.4.5.1 (Associations) says

    As endFeatures, the associationEnds of an Association are given a special semantics compared to other Features. Even if an associationEnd has a declared multiplicity other than 1..1, the associationEnd is required to effectively have multiplicity 1..1 as a participant in the Link. Note that the Feature Link::participant is declared readonly, meaning that the participants in a link cannot change once the link is created.

    If an associationEnd has a declared multiplicity other than 1..1, then this shall be interpreted as follows: For an Association with N associationEnds, consider the i-th associationEnd ei. The multiplicity, ordering and uniqueness constraints specified for ei apply to each set of instances of the Association that have the same (singleton) values for each of the N-1 associationEnds other than ei.

    Clause 8.3.3.3.3 (Feature) says

    isEnd : Boolean
    Whether or not the this Feature is an end Feature, requiring a different interpretation of the multiplicity of the Feature. An end Feature is always considered to map each domain instance to a single co-domain instance, whether or not a Multiplicity is given for it. If a Multiplicity is given for an end Feature, rather than giving the co-domain cardinality for the Feature as usual, it specifies a cardinality constraint for navigating across the endFeatures of the featuringType of the end Feature.

    That is, if a Type has n endFeatures, then the Multiplicity of any one of those end Features constrains the cardinality of the set of values of that Feature when the values of the other n-1 end Features are held fixed.

  • Reported: KerML 1.0a1 — Wed, 26 Apr 2023 14:47 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT
  • Attachments:

Redundancy in association end multiplicities, ordering, and uniqueness

  • Key: KERML-36
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    KerML association end textual notation/abstract syntax give multiplicity, ordering, and uniqueness that can be redundantly stated on the corresponding features of associated classifiers (association ends in SysML1.x/UML sense, see KERML-34 about terms), eg, in Occurrences:

    Occurrence::suboccurrences [1..*] {...}
    
    HappensDuring {end shorterOccurrence [1..*] subsets longerOccurrence.suboccurrences;}
    

    making it possible for multiplicities, ordering, and uniqueness to get out synch between the features, and potentially be inconsistent. See kerml-assoc-redundancy-issue-description-v2.pdf slides attached.

  • Reported: KerML 1.0a1 — Wed, 26 Apr 2023 14:35 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT
  • Attachments:

Number of association end feature values, semantics

  • Key: KERML-35
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    The specification says that association "end" features have exactly one value each (see KERML-34 for spec excerpts and definition of terms), but this semantics is not math/modeled.

  • Reported: KerML 1.0a1 — Wed, 26 Apr 2023 14:23 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Association participant features, misleading term and textual keyword

  • Key: KERML-34
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    The specification and models carry over the terms "association end" and "participant" from SysML 1.x, leaving the meaning of "participant" as it was, but changing the meaning of "association end" to be same as "participant", and providing no term equivalent to SysML 1.x "association end" (see below). This shift makes KerML/SysML 2 associations difficult to understand and discuss among current SysMLers (judging from experience during the submission process), and probably those new to SysML as well.

    The specification term "association end" refers to what SySML 1.x calls a "participant" property, a property of links (instances of associations) that each identify exactly one of the things being linked by each link. The library element Link has a feature named "participant", with exactly the same meaning as in SysML 1.x, that generalizes "association end" features, such as the source and target features of BinaryLink. The term "association end" in SysML 1.x refers to properties (typically) of associated classes that on each instance of one associated class identify (potentially zero or multiple) instances of the other associated class that are linked by the association. KerML can model these kind of features, but does not give a name for them.

    Clauses 7.4.5 (Associations) and 9.2.3.1 (Links Overview) say

    Associations are classifiers that classify links between things (see 9.2.3.1) At least two owned features of an association must be end features (see 7.3.4.2), its association ends, which identify the things being linked by (at the "ends" of) each link (exactly one thing per end, which might be the same thing).

    The end features of an association determine the participants in the links that are instances of the association and, as such, effectively have multiplicity of "1" relative to the association.

    The participant Feature of Link is the most general associationEnd, identifying the things being linked by (at the "ends" of) each Link (exactly one thing per end, which might be the same things).

    where Association::associationEnds identify participant features.

    The above use of "association end" in the specifiation is reflected in the textual syntax for assocations by the keyword "end" identifying these participant features. Clause 8.4.4.5.1 (Associations) says:

    n-aries have this form:

    uassoc A specializes Links::Link {
    end feature e1 subsets Links::Link::participant;
    end feature e2 subsets Links::Link::participant;
    ...
    end feature eN subsets Links::Link::participant; }
    

    The Link instance for an Association is thus a tuple of participants, where each participant is a single value of an associationEnd of the Association.

    The quoted text above is only about the equivalent of SysML 1.x participant properties, but might seem to current SysMLers to be about something equivalent to SysML 1.x association ends.

  • Reported: KerML 1.0a1 — Wed, 26 Apr 2023 14:09 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Succession end multiplicity defaults not documented

  • Key: KERML-29
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clause 8.4.4.6.2 (Binding Connectors) says

    binding f1 = f2;
    

    is equivalent to

    connector subsets Links::selfLinks {
      end feature thisThing redefines Links::SelfLink::thisThing references f1;
      end feature thatThing redefines Links::SelfLink::thatThing references f2; 
    

    while the next clause, 8.4.4.6.3 (Successions) says

    succession first f1 then f2;
    

    is equivalent to

    connector subsets Occurrences::happensBeforeLinks {
      end feature earlierOccurrence references f1
        redefines Occurrences::HappensBefore::earlierOccurrence;
      end feature laterOccurrence references f2
        redefines Occurrences::HappensBefore::laterOccurrence; }
    

    The similarity between the clauses implies the first/then notation is short for successions with multiplicity 1..1 on both ends, but the text does not say it, if that's the intention, and should be clarified in any case.

  • Reported: KerML 1.0a1 — Mon, 24 Apr 2023 15:07 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

End feature multiplicity textual notation

  • Key: KERML-26
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    Background

    Consider the flowing simple structure:

    struct Car {
      feature carEngine : Engine[1];
      feature carWheels : Wheel[4];
      
      connector carDrive : Drive
        from carEngine to carWheels;
    }
    

    The feature multiplicities in this model require that each instance of Car have exactly one Engine and exactly four Wheels. The model also includes a usage of the following association:

    assoc Drive {
      end feature driveEngine : Engine[0..1];
      end feature driveWheel : Wheel[2..4];
    } 
    

    The Drive end multiplicities require that every Engine is connected to 2 to 4 Wheels, while every Wheel is connected to at most 1 Engine. But each instance of the association Drive is a link between a single engine and a single wheel. The multiplicities of the end features of Drive are thus interpreted differently than those of the features of Car (but consistently with how UML and SysML v1 interpret association end multiplicity). Rather than constraining the values of the end features themselves, the end multiplicities constrain the number of links allowed when the value at one end is held fixed: if a value is given for the driveEngine, then there must be two to four Drive links from that driveEngine to different Wheels; if a value is given for the driveWheel, then there must be zero or one instances between that driveWheel and an Engine.

    For example, consider the following usage of Car that explicitly binds all the Car features:

    feature myCar : Car {
      feature :>> carEngine = myEngine;
      feature :>> carWheels =
        (leftFrontWheel, rightFrontWheel, leftRearWheel, rightRearWheel);
      
      connector :>> carDrive =
        ( Drive(myEngine, leftRearWheel),
          Drive(myEngine, rightRearWheel)
        );
    }
    

    The connector ends of the connector carDrive inherit their end multiplicities from the ends of the association Drive. The above model explicitly binds the carDrive connector to two Drive values:

    1. a connection from myEngine to leftRearWheel

    2. a connection from myEngine to rightRearWheel

    This satisfies the multiplicity constraint for Drive, because the carEngine is linked to two Wheels (presuming leftRearWheel and rightRearWheel are different) and each carWheel is connected to at most one Engine.

    Concern

    While the semantic interpretation of the multiplicity of end features is different than that of non-end features, the same textual notation is used in both cases. This can be confusing, making it seem like, e.g., each instance of Drive has 0 or 1 driveEngine and 2 to 4 driveWheels, which would be the case for regular features but not for end features.

    Proposal

    Change the textual notation so that the multiplicity of an end feature is placed immediately after the end keyword, rather than in the usual place for a feature declaration. For example:

    assoc Drive {
      end [0..1] feature driveEngine : Engine;
      end [2..4] feature driveWheel : Wheel;
    }
    

    This would not require a change in the abstract syntax.

  • Reported: KerML 1.0a1 — Fri, 21 Apr 2023 23:14 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Some bindings have optional connector end multiplicities

  • Key: KERML-27
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clauses 8.4.4.6.2 (Binding Connectors) and 7.4.6.3 (Binding Connector Declaration) says they have end multiplicity 1..1 on both ends:

    Binding connectors are binary connectors that require their source and target features to have the same values on each instance of their domain. They are typed by the library association SelfLink (which only links things in the modeled universe to themselves, see 9.2.3.1) and have end multiplicities of exactly 1. This requires a SelfLink to exist between each value of the source feature and exactly one value of the target feature, and vice-versa.

    The connector ends of a binding connector always have multiplicity 1..1.

    but there is no constraint for this on BindingConnector, which might be good because the libraries sometimes have optional mutiplicities, for example:

    Occurrences:
      binding unionsOf.union[0..1] = self[1];
    Transfers:
      private binding instant[0..1] of startShot[0..1] = endShot[0..1]
    Control Performances:
      binding loopBack of untilDecision.elseClause[0..1] = whileDecision[1];
    

    might be others.

    SelfLink connectors with one optional end multiplicity are equivalent to feature subsetting (without the inheritance restrictions), rather than the typical meaning of "bind". Perhaps these should have a different textual keyword?

  • Reported: KerML 1.0a1 — Sun, 23 Apr 2023 14:52 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Decision/MergePerformance element descriptions give incorrect modeling pattern

  • Key: KERML-28
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clause 9.2.9.1 (Control Performances Overview) says

    Successions going out of Steps typed by DecisionPerformance or its specializations must:
    • ...
    • be included in a Feature of its featuringBehavior that unions (see 7.3.2.7) all the outgoing
    Successions, and is bound to the outgoingHBLink of the Step (see 7.3.4.6 on feature chaining).

    Successions coming into Steps typed by MergePerformance or its specializations must:
    • ...
    • subset a Feature of its featuringBehavior that unions all the incoming Successions, and is bound to the incomingHBLink of the Step.

    but the Description sections of 9.2.9.2.1 (DecisionPerformance) and 9.2.9.2.7 (MergePerformance) say:

    All such Successions must subset the outgoingHBLink feature of the source DecisionPerformance.

    All such Successions must subset the incomingHBLink feature of the target MergePerformance.

    respectively. These allow outgoing/incomingHBLink to have values that are not identified by outgoing/incoming successions when none of the successions is traversed. The pattern in the overview above introduces a feature unioning the successions and binds it to a chain through decision/merge to outgoing/incomingHBLink, ensuring the HB links are identified by the successions.

  • Reported: KerML 1.0a1 — Mon, 24 Apr 2023 14:52 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Succession end multiplicity defaults not documented

  • Key: KERML_-15
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clause 8.4.4.6.2 (Binding Connectors) says

    binding f1 = f2;
    

    is equivalent to

    connector subsets Links::selfLinks {
      end feature thisThing redefines Links::SelfLink::thisThing references f1;
      end feature thatThing redefines Links::SelfLink::thatThing references f2; 
    

    while the next clause, 8.4.4.6.3 (Successions) says

    succession first f1 then f2;
    

    is equivalent to

    connector subsets Occurrences::happensBeforeLinks {
      end feature earlierOccurrence references f1
        redefines Occurrences::HappensBefore::earlierOccurrence;
      end feature laterOccurrence references f2
        redefines Occurrences::HappensBefore::laterOccurrence; }
    

    The similarity between the clauses implies the first/then notation is short for successions with multiplicity 1..1 on both ends, but the text does not say it, if that's the intention, and should be clarified in any case.

  • Reported: KerML 1.0a1 — Mon, 24 Apr 2023 15:07 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Some bindings have optional connector end multiplicities

  • Key: KERML_-13
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clauses 8.4.4.6.2 (Binding Connectors) and 7.4.6.3 (Binding Connector Declaration) says they have end multiplicity 1..1 on both ends:

    Binding connectors are binary connectors that require their source and target features to have the same values on each instance of their domain. They are typed by the library association SelfLink (which only links things in the modeled universe to themselves, see 9.2.3.1) and have end multiplicities of exactly 1. This requires a SelfLink to exist between each value of the source feature and exactly one value of the target feature, and vice-versa.

    The connector ends of a binding connector always have multiplicity 1..1.

    but there is no constraint for this on BindingConnector, which might be good because the libraries sometimes have optional mutiplicities, for example:

    Occurrences:
      binding unionsOf.union[0..1] = self[1];
    Transfers:
      private binding instant[0..1] of startShot[0..1] = endShot[0..1]
    Control Performances:
      binding loopBack of untilDecision.elseClause[0..1] = whileDecision[1];
    

    might be others.

    SelfLink connectors with one optional end multiplicity are equivalent to feature subsetting (without the inheritance restrictions), rather than the typical meaning of "bind". Perhaps these should have a different textual keyword?

  • Reported: KerML 1.0a1 — Sun, 23 Apr 2023 14:52 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Decision/MergePerformance element descriptions give incorrect modeling pattern

  • Key: KERML_-14
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clause 9.2.9.1 (Control Performances Overview) says

    Successions going out of Steps typed by DecisionPerformance or its specializations must:
    • ...
    • be included in a Feature of its featuringBehavior that unions (see 7.3.2.7) all the outgoing
    Successions, and is bound to the outgoingHBLink of the Step (see 7.3.4.6 on feature chaining).

    Successions coming into Steps typed by MergePerformance or its specializations must:
    • ...
    • subset a Feature of its featuringBehavior that unions all the incoming Successions, and is bound to the incomingHBLink of the Step.

    but the Description sections of 9.2.9.2.1 (DecisionPerformance) and 9.2.9.2.7 (MergePerformance) say:

    All such Successions must subset the outgoingHBLink feature of the source DecisionPerformance.

    All such Successions must subset the incomingHBLink feature of the target MergePerformance.

    respectively. These allow outgoing/incomingHBLink to have values that are not identified by outgoing/incoming successions when none of the successions is traversed. The pattern in the overview above introduces a feature unioning the successions and binds it to a chain through decision/merge to outgoing/incomingHBLink, ensuring the HB links are identified by the successions.

  • Reported: KerML 1.0a1 — Mon, 24 Apr 2023 14:52 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Type union, intersection, difference semantics

  • Key: KERML-8
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Type unioning, intersecting, and differing are described as

    Unioning, intersecting, and differencing are relationships between an owning type and a set of other types.
    1. Unioning specifies that the owning type classifies everything that is classified by any of the unioned types.
    2. Intersecting specifies that the owning type classifies everything that is classified by all of the intersecting types.
    3. Differencing specifies that the owning type classifies everything that is classified by the first of the differenced types but not by any of the remaining types.

    but this semantics is not math/modeled.

  • Reported: KerML 1.0a1 — Sun, 16 Apr 2023 16:26 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

isSufficient, semantics, expressiveness

  • Key: KERML-9
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Sufficient types are (Type::isSufficient=true) are described as

    A type gives conditions for what things must be in or not in its extent (sufficient and necessary conditions, respectively).

    ... the type places additional sufficiency conditions on its instances corresponding to all the necessary conditions.

    but this semantics is not math/modeled and the syntax cannot specify that only some necessary conditions are to correspond to sufficient ones.

  • Reported: KerML 1.0a1 — Sun, 16 Apr 2023 16:43 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Steps are not always time enclosed

  • Key: KERML-11
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clause 8.4.4.7.2 (Steps, under Behavior Semantics) says

    The checkStepSpecialization constraint requires that Steps specialize Performances::performances.

    checkStepEnclosedPerformanceSpecialization and checkStepSubperformanceSpecialization constraints require that a Step whose owningType is a Behavior or another Step specialize Performances::Performance::enclosedPerformance or, if it is composite, Performances::Performance::subperformance.

    checkStepOwnedPerformanceSpecialization constraint requires that a composite Step whose owningType is a Structure or a Feature typed by a Structure specialize Objects::Object::ownedPerformance.

    where enclosedPerformances, subperformances, and ownedPerformances (in)directly subset timeEnclosedOccurrences, the values of which happen during the occurrences "having" the value.

    The first constraint leaves open the possibility that steps might not happen during the occurrences they are steps of, bc Performances::performances is a step and subsets occurrences, rather than timeEnclosedOccurrences. This conflicts with the normal meaning of the term "step" (a terminology issue), which typically connotes (in library terms) performances that happen during the occurrences they are steps of.

    The second constraint prevents the possibility above for steps owned by behaviors or other steps, while the third only prevents it for composite steps owned by structures.

    The step keyword looks like it's sometimes used with other intentions than the constraints indicate. For example, in Observation.kerml:

    behavior ObserveChange { ...
      step transfer : TransferBefore[1] ... {
        /* Then send changeSignal to changeObserver. */ ... } ... }
    

    ↑ Is it intended that observechange occurrences timeenclose the entire transfer (all the way to it's arrival at its target), as required by the second constraint?

    struct ChangeMonitor { ...
      step startObservation { ... }
      step cancelObservation { ... }
    

    ↑ Is it intended that the values of start/CancelObservation can happen at other times than the ChangeMonitor occurrence referencing them, as allowed by the third constraint?

    Transfers::
      step transfers: Transfer[0..*] nonunique subsets performances, binaryLinks { ... }
      step messageTransfers: MessageTransfer[0..*] nonunique subsets transfers { ... }
      step flowTransfers: FlowTransfer[0..*] nonunique subsets transfers { ... }
      step transfersBefore: TransferBefore[0..*] nonunique subsets transfers, happensBeforeLinks { ... }
      step flowTransfersBefore: FlowTransferBefore[0..*] nonunique subsets flowTransfers, transfersBefore { ... }
    

    ↑ These are features of (effectively) Anything, including structures and behaviors, so sometimes they'll be time enclosed and sometimes not. For example:

    Occurrence::
      feature incomingTransfers: Transfers::Transfer[0..*] subsets Transfers::transfers { ... }
      feature outgoingTransfers: Transfers::Transfer[0..*] subsets Transfers::transfers { ... }
    

    ↑ will be time enclosed for transfers into/out of performances, but not objects, assuming the above are redefined as steps in behaviors or structures (or that features specialized from steps are also steps).

  • Reported: KerML 1.0a1 — Fri, 21 Apr 2023 15:22 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

direction, semantics

  • Key: KERML-10
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Feature direction (Feature::direction:FeatureDirectionKind) is described as

    in, out, inout: Specifies the direction of a feature, which determines what is allowed to change its values on instances of its domain:
    -in: Things "outside" the instance. These features identify things input to an instance.
    -out: The instance itself or things "inside" it. These features identify things output by an instance.
    -inout: Both things "outside" and "inside" the instance. These features identify things that are both input to and output by an instance.

    but this semantics is not math/modeled and depends on Kernel for instances changing over time.

  • Reported: KerML 1.0a1 — Fri, 21 Apr 2023 13:19 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT
  • Attachments:

Type union, intersection, difference semantics

  • Key: KERML_-8
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Type unioning, intersecting, and differing are described as

    Unioning, intersecting, and differencing are relationships between an owning type and a set of other types.
    1. Unioning specifies that the owning type classifies everything that is classified by any of the unioned types.
    2. Intersecting specifies that the owning type classifies everything that is classified by all of the intersecting types.
    3. Differencing specifies that the owning type classifies everything that is classified by the first of the differenced types but not by any of the remaining types.

    but this semantics is not math/modeled.

  • Reported: KerML 1.0a1 — Sun, 16 Apr 2023 16:26 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Steps are not always time enclosed

  • Key: KERML_-11
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clause 8.4.4.7.2 (Steps, under Behavior Semantics) says

    The checkStepSpecialization constraint requires that Steps specialize Performances::performances.

    checkStepEnclosedPerformanceSpecialization and checkStepSubperformanceSpecialization constraints require that a Step whose owningType is a Behavior or another Step specialize Performances::Performance::enclosedPerformance or, if it is composite, Performances::Performance::subperformance.

    checkStepOwnedPerformanceSpecialization constraint requires that a composite Step whose owningType is a Structure or a Feature typed by a Structure specialize Objects::Object::ownedPerformance.

    where enclosedPerformances, subperformances, and ownedPerformances (in)directly subset timeEnclosedOccurrences, the values of which happen during the occurrences "having" the value.

    The first constraint leaves open the possibility that steps might not happen during the occurrences they are steps of, bc Performances::performances is a step and subsets occurrences, rather than timeEnclosedOccurrences. This conflicts with the normal meaning of the term "step" (a terminology issue), which typically connotes (in library terms) performances that happen during the occurrences they are steps of.

    The second constraint prevents the possibility above for steps owned by behaviors or other steps, while the third only prevents it for composite steps owned by structures.

    The step keyword looks like it's sometimes used with other intentions than the constraints indicate. For example, in Observation.kerml:

    behavior ObserveChange { ...
      step transfer : TransferBefore[1] ... {
        /* Then send changeSignal to changeObserver. */ ... } ... }
    

    ↑ Is it intended that observechange occurrences timeenclose the entire transfer (all the way to it's arrival at its target), as required by the second constraint?

    struct ChangeMonitor { ...
      step startObservation { ... }
      step cancelObservation { ... }
    

    ↑ Is it intended that the values of start/CancelObservation can happen at other times than the ChangeMonitor occurrence referencing them, as allowed by the third constraint?

    Transfers::
      step transfers: Transfer[0..*] nonunique subsets performances, binaryLinks { ... }
      step messageTransfers: MessageTransfer[0..*] nonunique subsets transfers { ... }
      step flowTransfers: FlowTransfer[0..*] nonunique subsets transfers { ... }
      step transfersBefore: TransferBefore[0..*] nonunique subsets transfers, happensBeforeLinks { ... }
      step flowTransfersBefore: FlowTransferBefore[0..*] nonunique subsets flowTransfers, transfersBefore { ... }
    

    ↑ These are features of (effectively) Anything, including structures and behaviors, so sometimes they'll be time enclosed and sometimes not. For example:

    Occurrence::
      feature incomingTransfers: Transfers::Transfer[0..*] subsets Transfers::transfers { ... }
      feature outgoingTransfers: Transfers::Transfer[0..*] subsets Transfers::transfers { ... }
    

    ↑ will be time enclosed for transfers into/out of performances, but not objects, assuming the above are redefined as steps in behaviors or structures (or that features specialized from steps are also steps).

  • Reported: KerML 1.0a1 — Fri, 21 Apr 2023 15:22 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

isSufficient, semantics, expressiveness

  • Key: KERML_-9
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Sufficient types are (Type::isSufficient=true) are described as

    A type gives conditions for what things must be in or not in its extent (sufficient and necessary conditions, respectively).

    ... the type places additional sufficiency conditions on its instances corresponding to all the necessary conditions.

    but this semantics is not math/modeled and the syntax cannot specify that only some necessary conditions are to correspond to sufficient ones.

  • Reported: KerML 1.0a1 — Sun, 16 Apr 2023 16:43 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

direction, semantics

  • Key: KERML_-10
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Feature direction (Feature::direction:FeatureDirectionKind) is described as

    in, out, inout: Specifies the direction of a feature, which determines what is allowed to change its values on instances of its domain:
    -in: Things "outside" the instance. These features identify things input to an instance.
    -out: The instance itself or things "inside" it. These features identify things output by an instance.
    -inout: Both things "outside" and "inside" the instance. These features identify things that are both input to and output by an instance.

    but this semantics is not math/modeled and depends on Kernel for instances changing over time.

  • Reported: KerML 1.0a1 — Fri, 21 Apr 2023 13:19 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT
  • Attachments:

isAbstract, semantics

  • Key: KERML-6
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Abstract types (Type::isAbstract=true) are described as

    instances of this Type must also be instances of at least one of its specialized Types.

    but this semantics is not math/modeled.

  • Reported: KerML 1.0a1 — Sat, 15 Apr 2023 14:22 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

isPortion, semantics

  • Key: KERML-5
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Portion features (Feature::isPortion=true) are described as

    Portion features are composite features where the values cannot exist without the whole, because they are the “same thing” as the whole. (For example, the portion of a person's life when they are a child cannot be added or removed from that person's life.)

    but this semantics is not math/modeled, at least not in Core, which does not include models of time or space. A syntactic constraint that isPortion implies isComposite also seems to be missing.

  • Reported: KerML 1.0a1 — Thu, 13 Apr 2023 20:18 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

isComposite, semantics

  • Key: KERML-4
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Composite features (Feature::isComposite=true) are described as

    Values of a composite feature, on each instance of the feature's domain, cannot exist after the featuring instance ceases to exist. This only applies to values at the time the instance goes out of existence, not to other things in the co-domain that might have been values before that.

    but this semantics is not math/modeled and Core does not include models of time.

  • Reported: KerML 1.0a1 — Thu, 13 Apr 2023 20:12 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Dynamic multiplicity, semantics

  • Key: KERML-2
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Multiplicity is a feature of a type (feature or classifier), with natural numbers as its type (see description of KERML-1). The math semantics for feature multiplicity (rule 5 in 8.4.3.4, Features Semantics) refers to the multiplicity metaproperty on a feature f as model element, rather than the multiplicity feature on an instance of f 's featuring type, preventing it from covering multiplicity values that change over the life of an instance, and possibly not handling constant values either.

  • Reported: KerML 1.0a1 — Thu, 13 Apr 2023 19:32 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

isReadOnly, semantics

  • Key: KERML-3
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Read only features (Feature::isReadOnly=true) are described as

    Values of read only features on each instance of their domain are the same during the entire existence of that instance

    but this semantics is not model/mathed and depends on Kernel for instances existing in time.

  • Reported: KerML 1.0a1 — Thu, 13 Apr 2023 20:02 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Dynamic multiplicity, semantics

  • Key: KERML_-3
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Multiplicity is a feature of a type (feature or classifier), with natural numbers as its type (see description of KERML-1). The math semantics for feature multiplicity (rule 5 in 8.4.3.4, Features Semantics) refers to the multiplicity metaproperty on a feature f as model element, rather than the multiplicity feature on an instance of f 's featuring type, preventing it from covering multiplicity values that change over the life of an instance, and possibly not handling constant values either.

  • Reported: KerML 1.0a1 — Thu, 13 Apr 2023 19:32 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

isAbstract, semantics

  • Key: KERML_-7
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Abstract types (Type::isAbstract=true) are described as

    instances of this Type must also be instances of at least one of its specialized Types.

    but this semantics is not math/modeled.

  • Reported: KerML 1.0a1 — Sat, 15 Apr 2023 14:22 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

isPortion, semantics

  • Key: KERML_-6
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Portion features (Feature::isPortion=true) are described as

    Portion features are composite features where the values cannot exist without the whole, because they are the “same thing” as the whole. (For example, the portion of a person's life when they are a child cannot be added or removed from that person's life.)

    but this semantics is not math/modeled, at least not in Core, which does not include models of time or space. A syntactic constraint that isPortion implies isComposite also seems to be missing.

  • Reported: KerML 1.0a1 — Thu, 13 Apr 2023 20:18 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

isComposite, semantics

  • Key: KERML_-5
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Composite features (Feature::isComposite=true) are described as

    Values of a composite feature, on each instance of the feature's domain, cannot exist after the featuring instance ceases to exist. This only applies to values at the time the instance goes out of existence, not to other things in the co-domain that might have been values before that.

    but this semantics is not math/modeled and Core does not include models of time.

  • Reported: KerML 1.0a1 — Thu, 13 Apr 2023 20:12 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Classifier multiplicity, semantics

  • Key: KERML-1
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Multiplicity is a feature of a type (feature or classifier), with natural numbers as its type. For a feature f, the values of its multiplicity (as a feature) are allowed cardinalities for the collection of values on each instance of f 's featuring type, while for classifiers they are allowed cardinalities for the collection of its instances. Math semantics for feature multiplicity is available (rule 5 in 8.4.3.4, Features Semantics), but missing for classifier multiplicity. Is it intended that every instance of a classifier give the number of allowable instances of that classifier? What if there are no instances?

  • Reported: KerML 1.0a1 — Thu, 13 Apr 2023 19:06 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Classifier multiplicity, semantics

  • Key: KERML_-2
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Multiplicity is a feature of a type (feature or classifier), with natural numbers as its type. For a feature f, the values of its multiplicity (as a feature) are allowed cardinalities for the collection of values on each instance of f 's featuring type, while for classifiers they are allowed cardinalities for the collection of its instances. Math semantics for feature multiplicity is available (rule 5 in 8.4.3.4, Features Semantics), but missing for classifier multiplicity. Is it intended that every instance of a classifier give the number of allowable instances of that classifier? What if there are no instances?

  • Reported: KerML 1.0a1 — Thu, 13 Apr 2023 19:06 GMT
  • Updated: Tue, 9 Apr 2024 23:30 GMT

Names validatePackageFilterIsBoolean and validatePackageFilterIsModelEvaluable are wrong

  • Key: KERML-15
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The constraints validatePackageFilterIsBoolean and validatePackageFilterIsModelLevelEvaluable are owned by ElementFilterMembership and apply to its condition property. Therefore, they should be named validateElementFilterMembershipConditionIsBoolean and validateElementFilterMembershipConditionIsModelLevelEvaluable.

  • Reported: KerML 1.0a1 — Fri, 21 Apr 2023 21:25 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

validateItemFlowItemFeature documentation is wrong

  • Key: KERML-14
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The current documentation for validateItemFlowItemFeature is

    An ItemFlow must have at most one ownedFeature that is an ItemFlow.

    It should be “…that is an ItemFeature.”

  • Reported: KerML 1.0a1 — Fri, 21 Apr 2023 21:22 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Rename validateDatatypeSpecialization to validateDataTypeSpecialization

  • Key: KERML-16
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The constraint validateDatatypeSpecialization should be named validateDataTypeSpecialization, because the metaclass is named DataType, not Datatype.

  • Reported: KerML 1.0a1 — Fri, 21 Apr 2023 21:26 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

List of symbols incomplete

  • Key: KERML-30
  • Status: open  
  • Source: 88solutions ( Mr. Manfred R. Koethe)
  • Summary:

    The list of symbols shown in Clause 8.2.2.7 lacks several symbols. The symbols missing are ".", ".?", "===" and "!==".

  • Reported: KerML 1.0a1 — Sat, 22 Apr 2023 00:16 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Validation constraints are missing in the SysML abstract syntax

  • Key: KERML-32
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The following validation constraints are implied by textual descriptions in the specification, but are missing in the abstract syntax. They should be added, along with appropriate OCL.

    8.3.17.2 ExhibitStateUsage

    1. validateExhibitStateUsageReference – If an ExhibitStateUsage has an ownedReferenceSubsetting, then its referencedFeature must be a StateActionUsage.

    8.3.19.2 AssertConstraintUsage

    2. validateAssertConstraintUsageReference – If an AssertConstraintUsage has an ownedReferenceSubsetting, then its referencedFeature must be a ConstraintUsage.

    8.3.20.10 SatisfyRequirementUsage

    4. validateSatisfyRequirementUsageReference – If a SatisfyRequirementUsage has an ownedReferenceSubsetting, then its referencedFeature must be a RequirementUsage.

    8.3.24.2 IncludeUseCaseUsage

    5. validateIncludeUseCaseUsageReference – If an IncludeUseCaseUsage has an ownedReferenceSubsetting, then its referencedFeature must be a UseCaseUsage.

  • Reported: KerML 1.0a1 — Tue, 25 Apr 2023 20:48 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Typo in description of Connector::targetFeature

  • Key: KERML-65
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    In 8.3.4.5.3 Connector, in the description of targetFeature, the "p>" at the beginning of the paragraph should be deleted.

  • Reported: KerML 1.0a1 — Fri, 5 May 2023 21:02 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

The OCL for checkFeatureEndRedefinition is wrong

  • Key: KERML-17
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The documentation for the checkFeatureEndRedefinition constraint is

    If a Feature has isEnd = true and an owningType that is not empty, then, for each direct supertype of its owningType, it must redefine the endFeature at the same position, if any.

    However, the OCL for the constraint requires the redefinitions to be of owned endFeatures of the supertypes, which is inconsistent with the constraint documentation, and is also inconsistent with the discussion in Language Description subclauses for Associations and Connectors (7.4.5 and 7.4.6) and with the corresponding Semantics subclauses (8.4.4.5 and 8.4.4.6).

  • Reported: KerML 1.0a1 — Fri, 21 Apr 2023 21:30 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

validateRedefinitionFeaturingTypes documentation and constraint are wrong

  • Key: KERML-13
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The documentation for validateRedefinitionFeaturingTypes should state that it applies to Redefinition, not Subsetting. The documentation and OCL constraint should also use redefinedFeature and redefiningFeature, rather than subsettedFeature and subsettingFeature.

  • Reported: KerML 1.0a1 — Fri, 21 Apr 2023 21:19 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

7.4.1 Kernel Overview: Occurence instead of Object superclass

  • Key: KERML-60
  • Status: open  
  • Source: ProSTEP iViP Association ( Mr. Bertil Muth)
  • Summary:

    In clause 7.4.1 Kernel Overview, there is the following sentence:
    "For example, classes must directly or indirectly subclassify the library class Object"

    I assume the superclass mentioned should be Occurence, not Object.

  • Reported: KerML 1.0a1 — Wed, 3 May 2023 07:11 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Some Feature constraints have no description

  • Key: KERML-78
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The following constraints of Feature have no descriptions in the abstract syntax:

    • deriveFeatureFeaturingType
    • validateFeatureChainingFeatureNotOne
  • Reported: KerML 1.0a1 — Thu, 11 May 2023 03:31 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Typo in Grammar

  • Key: KERML-31
  • Status: open  
  • Source: 88solutions ( Mr. Manfred R. Koethe)
  • Summary:

    Clause 8.2.5.7.1
    The closing apostrophe at the end of line is missing:

    FunctionBody : Type =
    ';' | '{' FunctionBodyPart '}

    Also, in the list of reserved words, "assign" is reserved, but doesn't appear in any KerML grammar. (It is a SysML v2 keyword, though).

  • Reported: KerML 1.0a1 — Sat, 22 Apr 2023 00:42 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Incorrect OCL for validateFeatureChainingFeatureNotOne and validateFeatureChainingFeaturesNotSelf

  • Key: KERML-80
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    In the OCL for the Feature constraints validateFeatureChainingFeatureNotOne and validateFeatureChainingFeaturesNotSelf in the abstract syntax, the references to chainingFeatures (plural) should be chainingFeature (singular).

  • Reported: KerML 1.0a1 — Thu, 11 May 2023 03:44 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Typo in 7.4.7.2

  • Key: KERML-64
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    In 7.4.7.2 Behavior Declaration, in the sixth paragraph (before the "behavior Focus" example), in the last sentence, "superclassifer" should be "superclassifier".

  • Reported: KerML 1.0a1 — Fri, 5 May 2023 21:00 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

The checkFeatureValuationSpecialization constraint is incorrect

  • Key: KERML-89
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    In subclause 8.4.4.11 Feature Values Semantics, it states that

    The checkFeatureValuationSpecialization constraint requires that, if the featureWithValue has no explicit ownedSpecializations and is not directed, then it subsets the result parameter of the value Expression.

    However, the specification of checkFeatureValuationSpecialization in subclause 8.3.3.3.3 only requires

    If a Feature has a FeatureValue, then it must specialize the result of the value Expression of the FeatureValue.

    without the limitation that "the featureWithValue has no explicit ownedSpecializations and is not directed" (and the OCL is consistent with the textual description of the constraint).

  • Reported: KerML 1.0a1 — Sun, 11 Jun 2023 22:18 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

The checkFeatureEndSpecialization constraint should apply to Connectors as well as Associations

  • Key: KERML-19
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The checkFeatureEndSpecialization semantic constraint requires that

    If a Feature has isEnd = true and an owningType that is an Association, then it must directly or indirectly specialize Links::Link::participants from the Kernel Semantic Library.

    If a Connector is explicitly typed by one or more Associations, then it’s ends will redefine the corresponding Association ends and will thus also indirectly specialize Link::participants. However, if the Connector adds additional ends, then these will not redefine any Association ends and there is currently no requirement that these ends specialize Link::participants. In particular, the base Association Link has no ends, so when an n-ary Connector is implicitly typed by it, none of its ends will redefine Association ends, and so none of them will subset participants, which is semantically incorrect.

    The checkFeatureEndSpecialization constraint needs to be updated to also cover such cases.

  • Reported: KerML 1.0a1 — Fri, 21 Apr 2023 21:40 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

OCL errors in specialization constraints

  • Key: KERML-83
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    There are errors in the OCL for the following specialization constraints:

    8.3.3.3.3 Feature

    checkFeatureDataValueSpecialization and checkFeatureObjectSpecializationspecializesFromLibary should be specializesFromLibrary

    8.3.4.6.3 Step

    checkStepSpecialization – Should use specializesFromLibrary

  • Reported: KerML 1.0a1 — Fri, 19 May 2023 21:01 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

validateTypeAtMostOneConjugator OCL is wrong

  • Key: KERML-95
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The OCL for the validateTypeAtMostOneConjugator constraint references the Conjugator relationship, which does not exist. This should instead be Conjugation.

    Also, the constraint has no documentation.

  • Reported: KerML 1.0b1 — Tue, 11 Jul 2023 04:07 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

The description of deriveFeatureReferenceExpressionReferent is wrong

  • Key: KERML-94
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    In 8.3.4.8.4 FeatureReferenceExpression, the description of deriveFeatureReferenceExpressionReferent is

    The targetFeature of a FeatureChainExpression is the memberElement of its first ownedMembership that is not a ParameterMembership.

    This description should, instead, start "The referent of a FeatureReferenceExpression is the..."

  • Reported: KerML 1.0a1 — Mon, 3 Jul 2023 23:06 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

NamespaceImport Description Incorrect

  • Key: KERML-101
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Description
    2nd Sentence
    "If isRecursive = false, then only the visible Memberships of the importOwningNamespace are imported."

    The issue is that importedNamespace Memberships are imported, not importOwningNamespace Memberships as written;

    So it should read:

    "If isRecursive = false, then only the visible Memberships of the importedNamespace are imported."

  • Reported: KerML 1.0b1 — Sun, 9 Jul 2023 20:37 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

validateSpecificationSpecificNotConjugated Typo and over Constraint

  • Key: KERML-107
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Constraints section
    2nd sentence:
    "The specific Type of a Generalization cannot be a conjugated Type."
    1st issue, typo: Replace Generalization with Specialization

    2nd issue, serious: This prevents Conjugated Types from specializing the Conjugated Types of their originalTypes more general Types.

    We probably should allow Specialization between Conjugated Types if their originalTypes have the a Specialization relationship (in the same direction). Or maybe it's implied?

  • Reported: KerML 1.0b1 — Sun, 9 Jul 2023 22:02 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

OwningMembership Description ownedMemberElement typo

  • Key: KERML-102
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Description
    2nd Sentence
    "The ownedMemberElementM becomes an ownedMember of the membershipOwningNamespace."

    ownedMemberElementM does not exist, has an extra "M" at the end, should read:

    "The ownedMemberElement becomes an ownedMember of the membershipOwningNamespace."

  • Reported: KerML 1.0b1 — Sun, 9 Jul 2023 20:41 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

deriveFeatureOwnedSubsetting text references wrong attribute

  • Key: KERML-113
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Constraints
    deriveFeatureOwnedSubsetting
    "The ownedRedefinitions of a Feature are its ownedSpecializations that are Subsettings."
    Text should not be referring to the ownedRedefinitions, but to the ownedSubsetting

    Proposed text:
    "The ownedSubsettings of a Feature are its ownedSpecializations that are Subsettings."

  • Reported: KerML 1.0b1 — Sun, 9 Jul 2023 23:37 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

deriveElementIsLibraryElement Typo

  • Key: KERML-103
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Constraints
    deriveElementIsLibraryElement
    "isLibraryElement = libraryNamespace() <>null"
    There needs to be a space between the operator and the null.

    Should read:
    "isLibraryElement = libraryNamespace() <> null"

  • Reported: KerML 1.0b1 — Sun, 9 Jul 2023 20:43 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

FeatureMembership Description Typo

  • Key: KERML-115
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Description
    "A FeatureMembership is ... that is also a Featuring RelationshipFeature and the Type, ..."

    "RelationshipFeature" is not a LexicalToken.. this is a typo in the sentence.

    It probably should read:
    "that is also a Featuring relationship between the Feature and the Type," ...

  • Reported: KerML 1.0b1 — Mon, 10 Jul 2023 00:23 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Namespace Description Textual Errors

  • Key: KERML-100
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Namespace
    Description
    A Namespace is an Element that contains other Element, known as its members...
    There is a missing plurality on the second "Element" in the first sentence.

    "via Import Relationships with other Namespace."
    Probably need to at least pluralize Namespace since Relationships is plural, and maybe change "with other" to something else like "with target", or delete "with other Namespace", since it's not critical info as the Import relationship is not just "with" a Namespace, it is either with a Namespace or Membership.

    As well as a typo in the second sentence of the 2nd paragraph.
    "If a Membership specifies a memberName and/or memberShortName, then that
    those are names of the corresponding memberElement relative to the Namespace."
    Remove "that" from between "then" and "those"

  • Reported: KerML 1.0b1 — Sun, 9 Jul 2023 20:29 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

validateSpecializationSpecificNotConjugated documentation is wrong

  • Key: KERML-96
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The documentation for the constraint validateSpecializationSpecificNotConjugated is "The specific Type of a Generalization cannot be a conjugated Type." Generalization should be changed to Specialization.

  • Reported: KerML 1.0b1 — Tue, 11 Jul 2023 04:14 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

deriveMembershipMemberElementId text elementId typo

  • Key: KERML-99
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Constraint Text:
    The memberElementId of a Membership is the elementIf of its memberElement
    Should be "elementId", not "elementIf"

  • Reported: KerML 1.0b1 — Sun, 9 Jul 2023 20:17 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Semantic constraints for subtypes of LiteralExpression are missing

  • Key: KERML-18
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The Kernel Semantic Library model Performances includes features corresponding to each of the various kinds of LiteralExpression (e.g., literalBooleanEvaluations for LiteralBoolan, literalStringEvaluations for LiteralString, etc.; see KerML specification, 9.2.6.2). However, semantic constraints requiring the LiteralExpressions subclasses to specialize these features are missing in the abstract syntax (see KerML, 8.3.4.8). Adding these constraints would also allow the checkFeatureResultSpecialization constraint (see KerML, 8.3.3.3.3) to be simplified by removing the requirement that “If a Feature has an owningType that is a LiteralExpression it must directly or indirectly specialize the DataType from the ScalarValues package in the Kernel Data Types Library corresponding to the kind of LiteralExpression.” (since this would be automatically satisfied by the implied specializations for each kind of LiteralExpression and the {{checkFeatureResultSpecialization} constraint).

  • Reported: KerML 1.0a1 — Fri, 21 Apr 2023 21:34 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

deriveFeatureFeaturingType conflicts with owningType

  • Key: KERML-118
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Constraint
    deriveFeatureFeaturingType
    Feature.featuringType is shown as the union of all the typeFeaturings that feature it with the first type of a feature chain. But what is not included is the possible FeatureMembership.
    This conflicts with the fact that Feature.owningType subsets featuringType and Feature.owningType is the owningType of an owningFeatureMembership. (Bonus: there is no derived property for codifying that statement of the derived /owningType attribute).

    Resolution of this issue may be worth utilizing typeWithFeature in more places instead of featuringType

  • Reported: KerML 1.0b1 — Mon, 10 Jul 2023 01:11 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

OCL errors in validateFeatureChainingFeatureNotOne and validateFeatureChainingFeaturesNotSelf

  • Key: KERML-12
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    In the constraints validateFeatureChainingFeatureNotOne and validateFeatureChainingFeaturesNotSelf, the name chainingFeatures should be chainingFeature. Also, validateFeatureChainingFeatureNotOne needs documentation.

  • Reported: KerML 1.0a1 — Fri, 21 Apr 2023 21:16 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

deriveTypeFeatureMembership incorrect unioning

  • Key: KERML-117
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Constraints
    deriveTypeFeatureMembership
    featureMembership = ownedMembership->union(inheritedMembership->selectByKind(FeatureMembership))
    The unioning metaproperty should not be ownedMembership, that is too broad and conflicts text the unioning metaproperty should be ownedFeatureMembership

    Proposed text:
    featureMembership = ownedFeatureMembership->union(inheritedMembership->selectByKind(FeatureMembership))

  • Reported: KerML 1.0b1 — Mon, 10 Jul 2023 00:57 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

validateClassSpecialization is too strict

  • Key: KERML-122
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The documentation for the constraint validateClassSpecializtion states:

    A Class must not specialize a DataType and it can only specialize an Association if it is an AssociationStructure.

    with the OCL

    ownedSpecialization.general->
        forAll(not oclIsKindOf(DataType)) and
    not oclIsKindOf(AssociationStructure) implies
        ownedSpecialization.general->
            forAll(not oclIsKindOf(Association))
    

    However, an Interaction is both a Behavior, which is a kind of Class, and an Association, and, for example, the library interaction Transfer specializes both Performance (a behavior) and BinaryLink (an association). But the above constraint disallows this specialization.

    The validateClassSpecialization constraint needs to be updated to allow both AssociationStructures and Interactions to specialize Associations.

  • Reported: KerML 1.0b1 — Wed, 12 Jul 2023 20:29 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

deriveFeatureType is not correct

  • Key: KERML-151
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The deriveFeatureType constraint recursively accesses the types of the subsetted Features of a Feature. However, it does not take into account that subsetting relationships may be circular.

    Also, the description of the constraint states "If a Feature has chainingFeatures, then its types are the same as the last chainingFeature." However, the OCL actually unions the types of the last chainingFeature with the others.

  • Reported: KerML 1.0b1 — Fri, 4 Aug 2023 20:07 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

deriveTypeOwned TypeRelationship constraints have incomplete OCL

  • Key: KERML-112
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Constraints
    deriveTypeOwnedDifferencing, deriveTypeOwnedDisjoining, deriveTypeOwnedUnioning
    All 3 OCL derivation expressions are missing the attribute assignment "=" like all the other derive Constraints

  • Reported: KerML 1.0b1 — Sun, 9 Jul 2023 23:31 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Problems with IfThenElsePerformance

  • Key: KERML-77
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The Behavior ControlPerformances::IfThenElsePerformance specializes IfThenPerformance and IfElsePerformance. However, it does not declare any owned parameters (see 9.2.9.2.4). This violates the rule state in 7.4.7.2 Behavior Declaration that "If there is more than one superclassifier behavior, then every parameter from every superclassifier must be redefined by an owned parameter of the subclassifier." Following this rule would require IfThenElsePerformance to be declared with owned parameters, such as

    	behavior IfThenElsePerformance specializes IfThenPerformance, IfElsePerformance {		 
    		in ifTest;
    		in thenClause;
    		in elseClause;
    	}
    

    However, as also described in 7.4.7.2, "...each of the owned parameters of the subclassifier behavior must, in order, redefine the parameter at the same position of each of the superclassifier behaviors". This means that IfThenElsePerformance::ifTest has to redefine ifTest from both IfThenPerformance and IfElsePerformance, which is fine. But it also means that IfThenElsePerformance::thenClause has to redefine IfThenPerformance::thenClause and IfElsePerformance::elseClause, which is not what is intended. There is no way to follow this rule and have the third parameter of IfThenElsePerformance redefine the second parameter of IfElsePerformance.

  • Reported: KerML 1.0a1 — Thu, 11 May 2023 03:23 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Binary association ends always unique

  • Key: KERML-38
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    In the Links model library, BinaryLink::source/target are defined as

    assoc all BinaryLink specializes Link {
     feature participant: Anything[2] nonunique ordered redefines Link::participant;
     readonly end feature source: Anything[0..*] subsets participant;
     readonly end feature target: Anything[0..*] subsets participant; }
    

    making source/target unique by default (subsets don't inherit ordering/uniqueness). This prevents modelers from defining the corresponding features of associated classifiers as nonunique (see KERML-37), because nonunique is less restrictive than unique.

  • Reported: KerML 1.0a1 — Wed, 26 Apr 2023 15:19 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Legacy, so incorrect, wording in Anything Description

  • Key: KERML-177
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Description
    3rd sentence
    "Since FeatureTyping is a kind of Generalization, this means that Anything is also a generalization of things."
    FeatureTyping is a kind of Specialization, not Generalization. Recommend: "this means that Anything is the general Type of things."

  • Reported: KerML 1.0b1 — Sat, 16 Sep 2023 18:28 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Natural unnecessary explicit general type declaration

  • Key: KERML-175
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    GeneralTypes
    "DataValue
    Integer"
    Since Integer is an, indirect, specialization of DataValue, there does not need to be an explicit direct specialization.
    Probably a typo, as most other ScalarValues only have their immediate more general type listed.

  • Reported: KerML 1.0b1 — Sat, 16 Sep 2023 18:24 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

BaseFunctions::',' has a bad parameter declaration

  • Key: KERML-88
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    In the Kernel Function Library model BaseFunctions, in the declaration of the ',' function, the seq2 feature is supposed to be the second input parameter, but it is missing an in direction keyword.

  • Reported: KerML 1.0a1 — Sun, 4 Jun 2023 11:28 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Base Overview Typo

  • Key: KERML-176
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    3rd sentence of paragraph
    "They are specialized into most general DataType DataValue, the type of dataValues,
    the most general Feature typed by DataTypes, respectively (see 8.3.4.1)."
    This sentence is missing a "the" between "into" and "most"

  • Reported: KerML 1.0b1 — Sat, 16 Sep 2023 18:26 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Occurrences Overview Typo

  • Key: KERML-180
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    1st paragraph, last sentence
    "For example, the time and space taken by a room might have air moving in it it, as
    well as light, radio waves, and so on."
    Typo. The word "it" is repeated in succession, recommend removing one of them.

  • Reported: KerML 1.0b1 — Sat, 16 Sep 2023 18:36 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Validation constraints are missing in the KerML abstract syntax

  • Key: KERML-20
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The following validation constraints are implied by textual descriptions in the specification, but are missing in the abstract syntax. They should be added, along with appropriate OCL.

    8.3.3.1.10 Type

    validateTypeOwnedUnioningNotOne – A Type must not have exactly one ownedUnioning.

    validateTypeOwnedIntersectingNotOne – A Type must not have exactly one ownedIntersecting.

    validateTypeOwnedDifferencingNotOne – A Type must not have exactly one ownedDifferencing.

    8.3.3.3.3 Feature

    validateFeatureChainingFeatureConformance – Each chainingFeature (other than the last) must conform to all the featuringTypes of the next Feature in the chain.

    8.3.3.3.8 Redefinition

    validateRedefinitionDirectionConformance – If the redefinedFeature of a Redefinition has a non-null direction, then the redefiningFeature must have the same direction.

    8.3.3.3.10 Subsetting

    validateSubsettingMultiplicityConformance – If the subsettingFeature of a Subsetting has a multiplicity that is a MultiplicityRange, then this must be consistent with the MultiplicityRange (if any) of the subsettedFeature (if the multiplicity bounds are model-level evaluable).

    validateSubsettingUniquenessConformance – The subsettingFeature of a Subsetting must not have isUnique = false if the subsettedFeature has isUnique = true.

    8.3.4.5.2 BindingConnector

    validateBindingConnectorTypeConformance – Either the first end of a BindingConnector should conform to the second, or vice versa.

    8.3.4.5.3 Connector

    validateConnectorAssociationEnds – All associations typing a Connector must have the same number of associationEnds, which are the same as the number of relatedFatures of the Connector.
    [Note: See the statement in 7.4.6.2 Connector Declaration on this.]

    validateConnectorTypeFeaturing – If a Connector has an owningType or (non-implied) ownedTypeFeaturings, then each of its relatedFeatures must have some featuringType of the Connector as a direct or indirect featuringType.
    [Note: This validation constraint corresponds to the semantic constraint checkConnectorTypeFeaturing, in the case that the semantic constraint is not able to be satisfied by adding implied TypeFeaturings.]

    8.3.4.7.3 Expression
    validateExpressionResultExpressionMembership – An Expression must own at most one ResultExpressionMembership.

    8.3.4.7.4 Function
    validateFunctionResultExpressionMembership – A Function must own at most one ResultExpressionMembership.

    8.3.4.8.3 FeatureChainExpression

    validateFeatureChainExpressionConformance – The featuringTypes of the targetFeature of a FeatureChainExpression must conform to the result parameter of the argument Expression of the FeatureChainExpression.

    8.3.4.8.4 FeatureReferenceExpression

    validateFeatureReferenceExpressionReferentIsFeature – The first Membership of a FeatureReferenceExpression that is not a ParameterMembership must have a Feature as its memberElement.

    8.3.4.8.5 InvocationExpression

    validateInvocationExpressionParameterRedefinition – Each input parameter of an InvocationExpression must redefine a feature of a type of the InvocationExpression.

    validateInvocationExpressionNoDuplicateParameterRedefinition – Two different parameters of an InvocationExpression must not redefine the same feature of a type of the Invocationexpression.

    8.3.4.8.14 OperatorExpression

    validateOperatorExpressionCastConformance – If an OperatorExpression is for the cast operator (as), then the types of the result of the argument of an OperatorExpression must conform to the target types of the cast.

    8.3.4.8.15 SelectExpression

    validateSelectExpressionOperator – The operator of a SelectExpression must be “select”.

    8.3.4.10.2 FeatureValue

    validateFeatureValueOverriding – All Features directly or indirectly redefined by the featureWithValue of a FeatureValue must have only default FeatureValues.

    8.3.4.12.3 MetadataFeature

    validateMetadataFeatureMetaclassNotAbstract – The metaclass of a MetadataFeature must not be abstract.

    validateMetadataFeatureAnnotatedElement – The annotatedElement of a MetadataFeature must have an abstract syntax metaclass consistent with the annotatedElement declarations for the MetadataFeature.

    validateMetadataFeatureBody – Each ownedFeature of a MetadataFeature must have no declared name, redefine a Feature owned by a supertype of the MetadataFeature, either have no featureValue or a featureValue with a value Expression that is model-level evaluable, and only have ownedFeatures that also meet these restrictions.

  • Reported: KerML 1.0a1 — Fri, 21 Apr 2023 22:17 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Update Kernel Model Libraries for validateFeatureValueOverriding constraint

  • Key: KERML-184
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The approved resolution to issue KERML-20 added the validateFeatureValueOverriding constraint, which requires "All Features directly or indirectly redefined by the featureWithValue of a FeatureValue must have only default FeatureValues".

    1. The Transfers model in the Kernel Semantic library binds certain features that are intended to be overridden in user models, but such overriding now causes violations of the validateFeatureValueOverriding constraint:
      • Transfers::Transfer::isInstant
      • Transfers::SendPerformance::sentItem
      • Transfers::AcceptPerformance::acceptedItem
    2. In the ComplexFunctions model in the Kernel Function Library, the functions sum and product bind their result parameters. However, these results are overridden in the corresponding functions in RealFunctions, RationalFunctions and IntegerFunctions models, which violates the validateFeatureValueOverriding constraint. Similarly, the result of the VectorFunctions::vectorScalarMult function is overridden in its specialization cartesianScalarVectorMult, which also violates the constraint. Using a default feature value instead of binding would eliminate all these violations.
  • Reported: KerML 1.0b1 — Sat, 23 Sep 2023 21:16 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Transfer sourceOutput and targetInput directions

  • Key: KERML-195
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    In the Kernel Semantic Library Transfers model, the Transfer::source::sourceOutput feature has direction out and the Transfer::target::targetInput feature has direction in. In the ItemFlowEnds of an ItemFlow, these features are redefined, with the redefined Features being corresponding Features of the source and target Features of the ItemFlow. However, the validateRedefinitionDirectionConformance constraint added by the resolution to KERML-20 means that these ItemFlowEnd Features must also have directions out and in, respectively (or inout) – that is, that a flow must be from an output Feature to an input Feature. While this may make sense for the typical connection of the output parameter of one Step to the input parameter of another, it disallows the ability to flow e.g., from an input parameter of a Behavior to an input of one of its steps or from an output parameter of a step to an output of the containing Behavior.

  • Reported: KerML 1.0b1 — Sun, 15 Oct 2023 16:44 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Documentation of features in Transfers library model is wrong

  • Key: KERML-227
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The Kernel Standard Library model for Transfers includes the following features, documented in subclauses of 9.2.7.2:

    • 9.2.7.2.4 flowTransfers
    • 9.2.7.2.5 flowTransfersBefore
    • 9.2.7.2.7 messageTransfers
    • 9.2.7.2.11 transfers
    • 9.2.7.2.12 transfersBefore

    In all these cases, the "Element" kind is documented simply as "Feature". However, in the normative Transfers.kerml file, all of these features are actually declared as steps.

  • Reported: KerML 1.0b1 — Mon, 13 Nov 2023 18:48 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

DataFunctions::Min and Max should not be capitalized

  • Key: KERML-188
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The Min and Max functions have uppercase-initial names in DataFunctions. However, all the specializations of these functions in ScalarFunctions, NumericalFunctions, etc. have lowercase-initial names min and max. The names in DataFunctions should be the same.

  • Reported: KerML 1.0b1 — Tue, 3 Oct 2023 12:05 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Wrong documentation format for class Occurrence in Semantic Library

  • Key: KERML-198
  • Status: open  
  • Source: DEKonsult ( Mr. Hans Peter de Koning)
  • Summary:

    In standard library Occurrences.kerml the declaration for abstract class Occurrence still uses deprecated documentation preceding the declaration. It should be moved to a doc annotation inside the curly brackets.

  • Reported: KerML 1.0b1 — Fri, 20 Oct 2023 09:11 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Occurrences can be data values

  • Key: KERML-42
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    7.4.1 (Kernel Overview) says

    ... data types cannot also be classes or associations, or share instances with them.

    ... data types classify things that do not exist in time or space ...

    Clauses 8.4.4.2 (Data Types Semantics) and 8.4.4.3 (Classes Semantics) say:

    The Type Base::DataValue is disjoint with Occurrences::Occurrence and Links::Link,

    The Class Occurrences::Occurrence is disjoint with Base::DataValues

    but Occurrence::Occurrence and Base::DataValue are not disjoint in the libraries.

  • Reported: KerML 1.0a1 — Thu, 27 Apr 2023 16:03 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Reflective KerML abstract syntax model has inconsistencies

  • Key: KERML-25
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The reflective KerML model in the Kernel Semantic Library has the following inconsistencies with the normative KerML abstract syntax:

    1. The ReferenceSubsetting metaclass should be in the Core package, not the Kernel package.

    2. The feature Succession::transitionStep should not subset ownedFeature.

  • Reported: KerML 1.0a1 — Fri, 21 Apr 2023 22:56 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

KerML 7.4.7.2 Behavior Declaration: last example

  • Key: KERML-59
  • Status: open  
  • Source: ProSTEP iViP Association ( Mr. Bertil Muth)
  • Summary:

    In the last example of clause KerML 7.4.7.2 Behavior Declaration, at the top of page 157, there is the line

    binding picture = focus.picture;

    I assume this should be

    binding picture = shoot.picture;

    in order to be consistent with the declaration before.

  • Reported: KerML 1.0a1 — Wed, 3 May 2023 07:03 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Anything.self subsetting Inconsistent declaration with Base.kerml declaration

  • Key: KERML-178
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Features
    self : Anything

    {subsets selfSameLife}

    The subsetting is inconsistent with Base.kerml which has "feature self: Anything[1] subsets things chains things.that"

  • Reported: KerML 1.0b1 — Sat, 16 Sep 2023 18:33 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Update Kernel Semantic Library for validateRedefinitionDirectionConformance constraint

  • Key: KERML-182
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The approved resolution to issue KERML-20 added the validationRedefinitionDirectionConformance constraint. However, the Occurrences and TransitionPerformances models in the Kernel Model Library actually violate that constraint. They need to be updated so they do not.

    1. Occurrences::ObserveChange::transfer::source::sourceOutput should have direction out.
    2. TransitionPerformances::TransitionPerformance::accept should have direction in.
  • Reported: KerML 1.0b1 — Sat, 23 Sep 2023 20:56 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Connector declaration does not allow a feature value

  • Key: KERML-24
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The second line of the following does not parse:

    abstract connector c1;
    abstract connector c2 = c3; // Error: No viable alternative at input '='
    

    The reason for this is that the NaryConnectorDeclaration production uses FeatureDeclaration (see KerML 8.2.5.5.1):

    NaryConnectorDeclaration : Connector =
        FeatureDeclaration
        ( '(' ownedRelationship += ConnectorEndMember ','
            ownedRelationship += ConnectorEndMember
            ( ',' ownedRelationship += ConnectorEndMember )* ')' )?
    

    However, however FeatureDeclaration does not include ValuePart, which provides the syntax for feature values (see KerML 8.2.4.3):

    Feature =
        FeaturePrefix
        ( 'feature'? FeatureDeclaration
        | 'feature'
        | ownedRelationship += PrefixMetadataMember
        )
        ValuePart? TypeBody
    

    On the other hand, KerML 7.4.6.2 states that “A connector is declared as a feature (see 7.3.4.2) using the keyword connector”, and a feature declaration (in the informal sense) can, in general, include a feature value, so it would be expected to be allowable for a connector, too.

    Note that this is not a problem for item flows, which explicitly allows a ValuePart (KerML 8.2.5.9.2):

    ItemFlowDeclaration : ItemFlow =
        ( FeatureDeclaration ValuePart?
          ( 'of' ownedRelationship += ItemFeatureMember )?
          ( 'from' ownedRelationship += ItemFlowEndMember
            'to' ownedRelationship += ItemFlowEndMember )?
        | ( isSufficient ?= 'all' )?
          ownedRelationship += ItemFlowEndMember 'to'
          ownedRelationship += ItemFlowEndMember
    
  • Reported: KerML 1.0a1 — Fri, 21 Apr 2023 22:53 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Universal features can have many values

  • Key: KERML-56
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    [From Vince Molnar] Clause 9.2.12.2.7 (universalClock), Description, says

    universalClock is a single Clock that can be used as a default universal time reference.

    but the Clocks library shows it as a package-level feature, ie, it has no featuring type, which Clauses 7.3.4.1 Features (Overview) and 8.3.3.3.3 (Feature) explain as

    The domain of features with no explicit featuring types is the type Anything from the Base library model (see 9.2.2).

    The domain of a Feature with no featuringTyps is implicitly the most general Type Base::Anything from the Kernel Semantic Library.

    enabling everything in the universe (instances of Anything) to identify its own universal clock.

    The phrase "universalClock is a single Clock" above is worded as if universalClock were a class, rather than a feature, giving the impression of exactly one value for universalClock across all things, but there is no constraint for this. Similarly, library documentation for Occurrence::localClock says:

    By default this is the singleton universalClock.

    The term "singleton" usually refers to instances of a class, rather than values of a feature, giving the impression of exactly one value for universalClock across all things.

    Might be other features like this. For example, from the library:

    Observation::defaultMonitor[1] : ChangeMonitor {doc
      /* defaultMonitor is a single ChangeMonitor that can be used as a default. * }
    
    SpatialFrames::defaultFrame : SpatialFrame[1] { doc
      /* defaultFrame is a fixed SpatialFrame used as a universal default. */ }
    

    These are also top-level features that seem intended to be "universal" in the sense above.

  • Reported: KerML 1.0a1 — Mon, 1 May 2023 13:52 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Performances can be objects, behaviors can be structures

  • Key: KERML-43
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clause 9.2.5.1 (Objects Overview) says

    Objects and Performances do not overlap

    but Objects::Object and Performances::Performance are not disjoint in the libraries.

    Clause 7.4.4 (Structures) says

    Structures and behaviors do not overlap,

    but there is no constraint for this.

  • Reported: KerML 1.0a1 — Thu, 27 Apr 2023 18:04 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Spatial links can be occurrences

  • Key: KERML-44
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clause 9.2.4.1 (Occurrences Overview), under Temporal and Spatial Associations, describes temporal/spatial relations between occurrences, such as HappensBefore/Outside and HappensDuring/InsideOf, then says:

    The Links above to do not take up time or space, they are temporal and spatial relations between things that do (they are disjoint with LinkObject, see 9.2.5.1).

    but

    • Some links can be occurrences without being link objects (LinkObject specializes of Link and Object, but does not intersect them).
    • Spatial links are not disjoint with LinkObject or Occurrence in the libraries.
  • Reported: KerML 1.0a1 — Thu, 27 Apr 2023 18:44 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Subsetting::/owningType is mandatory

  • Key: KERML-54
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    In Clause 8.3.3.3.1 (Overview, Features Abstract Syntax), Figure 18 (Subsetting):

    • Subsetting::/owningFeature:Feature[1] narrows the multiplicity inherited from Type::/owningType[0..1] in Clause 8.3.3.1.1 (Overview, Types Abstract Syntax), Figure 10 (Specialization).
    • Redefinition::/owningFeature:Feature[0..1] subsets the above with the same name, which is not allowed, and widens the multiplicity back to the one on Type.

    This prevents subsettings from being defined without "affecting" the specializing feature (ie, modifying that feature as a model element). Compare to Subclassification, which leaves the inherited multiplicity as is for this purpose, in Clause 8.3.3.2.1 (Overview, 8.3.3.2 Classifiers Abstract Syntax), Figure 16 (Classifiers).

  • Reported: KerML 1.0a1 — Sun, 30 Apr 2023 14:41 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT
  • Attachments:

Link participant feature called an association end

  • Key: KERML-39
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Clause 9.2.3.1 (Links Overview) says

    The participant Feature of Link is the most general associationEnd, identifying the things being linked by (at the "ends" of) each Link (exactly one thing per end, which might be the same things).

    but the two places it appears in the Links model library

      readonly feature participant: Anything[2..*] nonunique ordered;
    
      feature participant: Anything[2] nonunique ordered redefines Link::participant;
    

    do not include the "end" keyword (are not end features), to prevent the semantics of end features from applying to the participant feature (see KERML-37).

  • Reported: KerML 1.0a1 — Wed, 26 Apr 2023 15:24 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

The MetadataFeature::metaclass multiplicity is too restrictive

  • Key: KERML-90
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The property MetadataFeature::metaclass has multiplicity 0..1. Since it also redefines type, this means that a MetadataFeature can only have a single type, which must be a Metaclass.

    In SysML, MetadataFeature is specialized to MetadataUsage, which is also a specialization of ItemUsage. MetadataUsage::metadataDefinition redefines MetadataFeature::metaclass, but its type is still Metaclass, with the intent that KerML Metaclasses, as well as SysML MetadataDefinitions, can be used to define SysML MetadataUsages.

    However, the checkMetadataUsageSpecialization constraint requires that a MetadataUsage specialize the SysML library usage Metadata::metadataItems, which is typed by Metadata::MetadataItem. The base definition Metadata::MetadataItem specializes both Metaobjects::Metaobject from KerML and Items::Item from SysML.

    This works without problem if a MetadataUsage is actually typed by a SysML MetadataDefinition. Since all MetadataDefinitions subclassify Metadata::MetadataItem, the single type of the MetadataUsage will be the specializing MetadataDefinition that is declared for it. However, if a MetadataUsage is typed by a KerML Metaclass that is not a subclassification of Metadata::MetadataItem, then the implied specialization of Metadata::metadataItems will result in the MetadataUsage implicitly having Metadata::MetadataItem as a type in addition to the declared Metaclass.

    And this violates the multiplicity of MetadataFeature::metaclass.

  • Reported: KerML 1.0a1 — Tue, 13 Jun 2023 17:48 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Car necessary and sufficiency example

  • Key: KERML-105
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Last Paragraph
    "For example, if Car requires all instances to be four-wheeled (necessary), and then is also is indicated as sufficient, its extent will include all four wheeled things and no others."

    "then is also is indicated" is not proper English.

    Should probably be:
    "For example, if Car requires all instances to be four-wheeled (necessary), and is also indicated as sufficient, its extent will include all four wheeled things and no others."

    Example also does not do a good job of showing how the "all" on Cars enforces sufficiency. But the whole necessary/sufficient semantics is another Issue KERML-9

  • Reported: KerML 1.0b1 — Sun, 9 Jul 2023 21:48 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Type Membership Multiplicity text conflict

  • Key: KERML-104
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Forth paragraph last sentence
    "A membership that would otherwise be imported is also hidden by an inherited memberships with the same member name, similarly to how it would be
    hidden by a conflicting owned membership (see 7.2.5)."
    Multiplicity conflict between "an" and "memberships"
    There is also no need to have the word "also".

    Text should read:
    "A membership that would otherwise be imported is hidden by an inherited membership with the same member name, similarly to how it would be hidden by a conflicting owned membership (see 7.2.5)."

  • Reported: KerML 1.0b1 — Sun, 9 Jul 2023 21:23 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Occurrences do not identify local spatial frame

  • Key: KERML-62
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Occurrence::localClock:Clock identifies a "time reference for this Occurrence" (9.2.4.2.13 Occurrence), but no feature is defined for a local spatial frame to identify a spatial reference for it (i.e., occurrences refer to a clock to measure time, but not a measuring rod for space).

  • Reported: KerML 1.0a1 — Wed, 3 May 2023 17:54 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

InsideOf association end feature redefines cross feature

  • Key: KERML-158
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    In Occurrences::InsideOf, in one of the end features

    end feature smallerSpace: Occurrence[1..*] redefines source, largerSpace.spaceEnclosedOccurrences;

    the second redefinition should be subsetting (it's a cross feature).

  • Reported: KerML 1.0b1 — Tue, 5 Sep 2023 18:00 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

oclAsType applied to resolveGlobal

  • Key: KERML-138
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    The signature of resolveGlobal is

    resolveGlobal(qualifiedName : String) : Membership [0..1]
    

    while uses of it sometimes apply oclAsType to the result, as in

    validateRedefinitionFeaturingTypes
    let anythingType: Type =
    subsettingFeature.resolveGlobal('Base::Anything').oclAsType(Type) in ...
    

    but Membership isn't a Type. Comparing to the body of specializesFromLibrary:

    specializesFromLibrary(libraryTypeName : String) : Boolean
    body: let mem : Membership = resolveGlobal(libraryTypeName) in
    mem <> null and mem.memberElement.oclIsKindOf(Type) and
    specializes(mem.memberElement.oclAsType(Type))
    

    I gather a memberElement navigation is needed, as in

    let anythingType: Type = subsettingFeature.resolveGlobal('Base::Anything').memberElement.oclAsType(Type) in
    

    Searching on "resolveGlobal" finds quite a few missing memberElement s, eg, validateSubsettingFeaturingTypes, checkStepSpecialization, checkOperatorExpressionSpecialization, maybe others.

  • Reported: KerML 1.0b1 — Thu, 3 Aug 2023 14:09 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Textual Syntax allows multiple ConjugationParts on a Type

  • Key: KERML-109
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:
    TypeDeclaration : Type =
    ( isSufficient ?= 'all' )? Identification
    ( ownedRelationship += OwnedMultiplicity )?
    ( SpecializationPart | ConjugationPart )+
    TypeRelationshipPart*
    

    Specifically the "( SpecializationPart | ConjugationPart )+" I don't think should be 1 or more, aka it should not have the "+" at the end.
    This allows legal syntactic constructs that do have multiple ConjugationParts or ConjugationParts and SpecializationParts.
    Multiple ConjugationParts or ConjugationParts and SpecializationParts appears to be against the Abstract Syntax.

    A better syntax may be "( SpecializationPart+ | ConjugationPart )" if you really want to keep multiple SpecializationParts

  • Reported: KerML 1.0b1 — Sun, 9 Jul 2023 22:13 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Protected membership inheritance through Specialization type

  • Key: KERML-106
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Last paragraph second sentence
    "Protected memberships are all owned and inherited memberships of the general type whose visibility declared as protected"

    Missing part of verb phrase: whose visibility IS declared as protected

    Should read:
    "Protected memberships are all owned and inherited memberships of the general type whose visibility is declared as protected"

  • Reported: KerML 1.0b1 — Sun, 9 Jul 2023 21:53 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Disjoining textual notation typo on disjoiningType

  • Key: KERML-111
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Both the Disjoining and OwnedDisjoining are missing a 'g' from the "disjoinginType = FeatureChain" parts

    Disjoining =
    ( 'disjoining' Identification )?
    'disjoint'
    ( typeDisjoined = [QualifiedName]
    | typeDisjoined = FeatureChain
    { ownedRelatedElement += typeDisjoined }
    )
    'from'
    ( disjoiningType = [QualifiedName]
    | disjoinginType = FeatureChain
    { ownedRelatedElement += disjoiningType }
    )
    RelationshipBody
    
    OwnedDisjoining : Disjoining =
    disjoiningType = [QualifiedName]
    | disjoinginType = FeatureChain
    { ownedRelatedElement += disjoiningType }
    
  • Reported: KerML 1.0b1 — Sun, 9 Jul 2023 23:27 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Conjugation Textual Redundant Word

  • Key: KERML-108
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    First paragraph last sentence
    "Features with with no direction or direction inout in the original type are inherited without change."
    Features WITH NO direction... remove second "with"

    "Features with no direction or direction inout in the original type are inherited without change."

  • Reported: KerML 1.0b1 — Sun, 9 Jul 2023 22:06 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

FeatureDeclaration ConjugationPart lexical element incorrect reference

  • Key: KERML-114
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    FeatureDeclaration ... ConjugationPart )? | FeatureSpecializationPart | FeatureConjugationPart ) ...

    FeatureConjugationPart definition does not exist... probably meant just ConjugationPart

    Proposed Text:

    FeatureDeclaration : Feature =
    ( isSufficient ?= 'all' )?
    ( FeatureIdentification
    ( FeatureSpecializationPart | ConjugationPart )?
    | FeatureSpecializationPart
    | ConjugationPart
    )
    FeatureRelationshipPart*
    
  • Reported: KerML 1.0b1 — Sun, 9 Jul 2023 23:42 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

checkFeatureSubobjectSpecialization incorrect Font

  • Key: KERML-170
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    checkFeatureSubobjectSpecialization
    "A composite Feature typed..."
    Starting at "typed" the words are still in the Font for code
    even though it should be back to the font for regular descriptive text.

  • Reported: KerML 1.0b1 — Sat, 16 Sep 2023 18:11 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Typo in Conjugation Description

  • Key: KERML-167
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Description
    1st paragraph 5th line
    "originalType are considered to have an effective direction of in in the originalType."
    The 2nd "originalType" is a typo and should be "conjugatedType" to be correct.

  • Reported: KerML 1.0b1 — Sat, 16 Sep 2023 17:49 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Misidentified non-terminals and misspelled non-terminals in the EBNF

  • Key: KERML-162
  • Status: open   Implementation work Blocked
  • Source: Georgia Institute of Technology ( Dr. Richard Wallace)
  • Summary:
    MetaclassificationExpression : OperatorExpression =
    ownedRelationship += MetadataArgumentMember
    ( operator = MetaClassificationTestOperator
    ownedRelationship += TypeReferenceMember
    | operator = MetaCastOperator
    owendRelationsip += TypeResultMember
    )
    

    The non-terminal "MetaClassificationTestOperator" does not exist. Should this be "MetaclassificationOperator" in the EBNF?

    The ownedRelationship is misspelled "owendRelationsip" in the EBNF. Correct the spelling.

  • Reported: KerML 1.0b1 — Tue, 5 Sep 2023 18:56 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Feature isDerived metaproperty Typo

  • Key: KERML-169
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    "Whether the values of this Feature can always be computed from the values of other Feature."
    "Feature" at the end of the sentence should be pluralized. "... values of other Features."

  • Reported: KerML 1.0b1 — Sat, 16 Sep 2023 18:09 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

unknown non-terminal reference in EBNF

  • Key: KERML-160
  • Status: open   Implementation work Blocked
  • Source: Georgia Institute of Technology ( Dr. Richard Wallace)
  • Summary:

    In the EBNF:

    MetaclassificationExpression : OperatorExpression =
    ownedRelationship += MetadataArgumentMember
    ( operator = MetaClassificationTestOperator
    ownedRelationship += TypeReferenceMember
    | operator = MetaCastOperator
    owendRelationsip += TypeResultMember
    )
    

    There is no non-terminal named "MetaCastOperator" in the EBNF. Should this be "CastOperator" instead?

  • Reported: KerML 1.0b1 — Tue, 5 Sep 2023 19:05 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

No production for nonterminal

  • Key: KERML-164
  • Status: open  
  • Source: Georgia Institute of Technology ( Dr. Richard Wallace)
  • Summary:

    In the production for FeatureDeclaration The nonterminal <FeatureConjugationPart> does not exist.

    FeatureDeclaration : Feature =
    ( isSufficient ?= 'all' )?
    ( FeatureIdentification
    ( FeatureSpecializationPart | ConjugationPart )?
    | FeatureSpecializationPart
    | FeatureConjugationPart
    )
    FeatureRelationshipPart*
    
  • Reported: KerML 1.0b1 — Thu, 14 Sep 2023 01:33 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Comment textual syntax defined differently to implementation

  • Key: KERML-191
  • Status: open  
  • Source: itemis AG ( Dr. David Akehurst)
  • Summary:

    Example Vehicle Example/VehicleDefinitions.kerml does not parse if the grammar from the document is used.

    Comment is defined in the document as

    Comment =
      'comment' Identification
      (  'about'  Annotation ( ',' Annotation )*  )?
     REGULAR_COMMENT
    

    and in the implementation as

    Comment returns SysML::Comment :
    	( 'comment' Identification?  ('about'  Annotation  ( ',' Annotation )* )?  )?
    	REGULAR_COMMENT
    ;
    
  • Reported: KerML 1.0b1 — Wed, 4 Oct 2023 14:00 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

OwnedExpression missing ConditionalBinaryOperatorExpression

  • Key: KERML-190
  • Status: open  
  • Source: itemis AG ( Dr. David Akehurst)
  • Summary:

    ConditionalBinaryOperatorExpression appears to be unused and Simple Tests/Filtering.kerml fails to parse - it contains a ConditionalBinaryOperatorExpression

    I think the problem is that ConditionalBinaryOperatorExpression is missing from the definition of OwnedExpression

       OwnedExpression
            = ConditionalExpression
            | BinaryOperatorExpression
            | UnaryOperatorExpression
            | ClassificationExpression
            | MetaclassificationExpression
            | ExtentExpression
            | PrimaryExpression
        ;
    
  • Reported: KerML 1.0b1 — Wed, 4 Oct 2023 13:57 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Feature Chain relationships are inconsistent with the concrete syntax

  • Key: KERML-171
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    The list of 7 relationships is inconsistent with the concrete syntax in 8.2
    Specifically while all 7 of the relationships do offer feature chain syntax, the list is missing an 8th relationship
    8.2.4.1.3 Conjugation
    page 87
    Either Conjugation should not offer featureChains in either the conjugatedType or originalType or they should be added to the list

  • Reported: KerML 1.0b1 — Sat, 16 Sep 2023 18:15 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

non-terminal does not exist in the specification

  • Key: KERML-189
  • Status: open  
  • Source: Georgia Institute of Technology ( Dr. Richard Wallace)
  • Summary:

    The non-terminal <MetaClassificationTestOperator> does not exist in the specification. This is believed to be a typographical error, and the non-terminal should be <MetaclassificationOperator>.

  • Reported: KerML 1.0b1 — Wed, 4 Oct 2023 12:21 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Model Interchange Overview Typo

  • Key: KERML-181
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    2nd paragraph, indented, first sentance
    "A project is a set of root namespaces (see 7.2.5.3 and 8.2.3.4.1), including all elements in the ownerhship
    trees of those namespaces"...
    ownerhship is spelled wrong, has extra h in the middle: ownership

  • Reported: KerML 1.0b1 — Sat, 16 Sep 2023 18:37 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

checkAssociationStructureSpecialization invalid reference

  • Key: KERML-179
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    checkAssociationStructureSpecialization
    specializesFromLibrary("Objects::ObjectLink")
    No such thing as "Objects::ObjectLink" in KerML, text references "Objects::LinkObject" which does exist

  • Reported: KerML 1.0b1 — Sat, 16 Sep 2023 18:35 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

ClassifierDeclaration concrete syntax typo

  • Key: KERML-172
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    ClassifierDeclaration : ...
    ( SuperclassingPart | ConjugationPart )?
    RelationshipPart*

    RelationshipPart token does not exist in concrete syntax. Believe this is meant to be TypeRelationshipPart*

  • Reported: KerML 1.0b1 — Sat, 16 Sep 2023 18:17 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Classifier Description Typo

  • Key: KERML-173
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Description
    Last sentence in 2nd bullet
    Note that his means that ..
    Typo. Should be "this" means that..

  • Reported: KerML 1.0b1 — Sat, 16 Sep 2023 18:18 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Annex A (Model Execution) minor errors

  • Key: KERML-200
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Annex A (Model Execution) has some minor errors, including:

    Spelling (multiple places):

    • modelled/ing => modeled/ing
    • assocation => association
    • multiplities => multiplicities

    Cross reference missing, "Clause" => "A.3.2"

    A.3.3 (One-to-one connectors)

    • second bullet list, cross reference missing, "Clause" => "A.3.2"
    • near end, in MyBikeWheel-Fork-BWF-Link, hypens => underscores

    A.3.4 (One-to-unrestricted connectors), in second code block

    • MyBasket2_BikeFork1_BBF_Link => MyBikeBasket2_Fork1_BBF_Link
    • MyBikeFork1_Basket1_BBF_Link => MyBikeBasket1_Fork1_BBF_Link
    • MyBikeFork1_Basket2_BBF_Link => MyBikeBasket2_Fork1_BBF_Link

    A.3.5 (Timing for structures), near end, MyBike_While_Fork2End_Link => MyBikeEnd_While_Fork2End_Link

    A.3.6 (Timing for behaviors, Sequences), third to last line (step redefines dry : MyShip [1]), dry => ship.

    A.3.8 (Timing for behavior, Changing feature values), in the code block just after the paragraphs starting

    • "Instantiation step 6.b.i. the start of 6.c.i produces", insert "redefines" as a separate word between the two "feature startShot".
    • "The third of instantiation step 6.b.ii and third start of 6.c.ii produces", move "dry.dried.endShot" to just before the following semi-colon and precede it by "chains ".
    • "FeatureWritePerformances ensure when they finish that", insert "in " before "redefines onOccurrence" and "redefines replacementValues (three times each).
    • "The first of instantiation step 6.b.ii and first start of 6.c.ii produces", in "feature redefines onOccurrence", feature => in
  • Reported: KerML 1.0b1 — Fri, 20 Oct 2023 14:20 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT
  • Attachments:

Additional problems with deriveFeatureType

  • Key: KERML-232
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    In addition to the problems addressed in KERML-151, the deriveFeatureType constraint has the following additional problems:

    1. If a Feature is conjugated, then the validateSpecializationSpecificNotConjugated constraint prohibits the Feature from being the specific Type in either FeatureTypings or Subsettings. Nevertheless, one would expect it to have the same types as the originalType that it is conjugating (assuming that is, indeed, a Feature).
    2. The description of deriveFeatureType says that the resulting set of types has "all redundant supertypes removed". This should be interpreted to mean that any Type for which there is some conforming subtype should be removed from the set, not just that duplicates of the same Type are removed (as in the current OCL).
  • Reported: KerML 1.0b1 — Wed, 22 Nov 2023 20:40 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

validateRedefinitionDirectionConformance does not account for conjugation

  • Key: KERML-194
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The description of the validateRedefinitionDirectionConformance constraint (added by the resolution to KERML-20) is

    If the redefinedFeature of a Redefinition has direction in or out, then the redefiningFeature must have the same direction. If the redefinedFeature has direction inout, then the redefiningFeature must have a non-null direction.

    Consistent with this, the OCL for the constraint directly checks the direction property of the redefinedFeature. However, this does not take into account that the redefinedFeature may be inherited from a Type that is conjugated, reversing the direction of its directed Features. To account for this, the Type::directionOf operation needs to be used instead of Feature::direction.

  • Reported: KerML 1.0b1 — Sun, 15 Oct 2023 15:20 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Association SourceType Cardinality Contradiction

  • Key: KERML-236
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    "Associations with more than two association ends ("n-ary") have only target types, no source types."
    related to KERML-159 and KERML-76,
    On page 170
    deriveAssociationSourceType and deriveAssociationTargetType contradict that with a source type always being specified as the first related type

  • Reported: KerML 1.0b1 — Tue, 21 Nov 2023 21:01 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Weird Concrete Syntax for ConditionalExpression

  • Key: KERML-193
  • Status: open  
  • Source: itemis AG ( Dr. David Akehurst)
  • Summary:

    ConditionalExpression = 'if' ArgumentMember '?' ArgumentExpressionMember 'else' ArgumentExpressionMember ;

    e.g. if x ? y else z

    either use symbols or words.
    Not half and half!

    if x then y else z

    OR

    if x ? y : z

  • Reported: KerML 1.0b1 — Mon, 9 Oct 2023 11:35 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Many mistakes and differences to implementation

  • Key: KERML-192
  • Status: open  
  • Source: itemis AG ( Dr. David Akehurst)
  • Summary:

    There are many typos and mistakes in the grammar as written in the document
    I have created separate issues for some, but there are so many I don't have time to list them all !

    Also the grammar in the document and the grammar in the pilot implementation are different in many places,
    also too many to list.

  • Reported: KerML 1.0b1 — Wed, 4 Oct 2023 14:03 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

No textual syntax or derivation rules for isDirected

  • Key: KERML-238
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    8.2.5.5 Connectors Concrete Syntax
    8.3.4.5.1 Connectors Abstract Syntax - Overview
    8.3.4.5.3 Connector - Attributes
    The Connector Abstract Syntax and Attributes section both show a isDirected : Boolean attribute.
    Neither show isDirected as a derived attribute, and there is no derivation constraint,
    but there is also no textual notation to allow language users to set the attribute to true.
    As far as I can tell, it will always be false, even though the description of the attribute states,
    at least for binary connectors, there should be times where it could be true.

  • Reported: KerML 1.0b1 — Tue, 21 Nov 2023 21:21 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Link Participant Plurality Typo in OCL

  • Key: KERML-237
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Constraints
    checkFeatureEndSpecialization
    "isEnd and owningType <> null and owningType.oclIsKindOf(Association) implies specializesFromLibrary("Links::Link::participants")"
    "Links::Link::participants" does not exist, probably meant "Links::Link::participant"

  • Reported: KerML 1.0b1 — Tue, 21 Nov 2023 21:16 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Typo in Multiplicity Ranges Semantics

  • Key: KERML-241
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    2nd paragraph (of page), 1st sentence
    "The checkMultiplicityRangeExpressionTypeFeaturing constraint requirs that the bound Expressions of
    a MultiplicityRange have the same featuringTypes as the MultiplicityRange."
    There is a typo, a misspelling, of the word "requires". "constraint requirs that" should be "constraint requires that"

  • Reported: KerML 1.0b1 — Tue, 21 Nov 2023 22:01 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Typo in Multiplicities Overview

  • Key: KERML-240
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Last paragraph, first sentence
    "If a multiplicity feature is declared in the body of a type, then then this becomes be the multiplicity of the type."
    Two typos exist, 'then' is repeated, also the word 'be' is not proper English. Recommend:
    "If a multiplicity feature is declared in the body of a type, then this becomes the multiplicity of the type."

  • Reported: KerML 1.0b1 — Tue, 21 Nov 2023 21:58 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Error in Expression modelLevelEvaluable operation OCL

  • Key: KERML-248
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Operations
    modelLevelEvaluable
    I'm not convinced the OCL expression is the same as the lexical explanation directly above it.
    Also the OCL may just be wrong in the 6th line
    "f.ownedFeature->isEmpty() f.valuation = null and or"
    This OCL needs to be very carefully looked at to align with the lexical explanation directly above it.
    I didn't spend more time on this but there were other concerns I had about the Relationships check and passing visited without adding itself to the visited list.
    It could be as simple as "((directionOf(f) = ... result) and f.ownedFeature->isEmpty() and f.valuation = null) or"

  • Reported: KerML 1.0b1 — Sun, 3 Dec 2023 02:58 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Typo in checkAssociationBinarySpecialization OCL

  • Key: KERML-242
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Constraints
    checkAssociationBinarySpecialization
    "ownedEndFeature->size() = 2 implies specializesFromLibrary("Links::BinaryLink)"
    Missing a quotation mark " after Links::BinaryLink

    Related but possible issue?
    Restricting this to ownedEndFeature instead of associationEnd can cause contradictions with inherited end features
    Users could end up inheriting from an n-ary association and only redefine 2 of them?

  • Reported: KerML 1.0b1 — Tue, 21 Nov 2023 22:19 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Typo in modelLevelEvaluable Operation text

  • Key: KERML-247
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Operations
    modelLevelEvaluable
    2nd paragraph, first sentence
    "An Expression that is not otherwise specialized is model-level evaluable if all of it has no
    ownedSpecialziations and all its (non-implicit) features are..."
    The word "ownedSpecialziations" is spelled wrong, it is missing an i between the l and z.
    It should be "ownedSpecializiations"

  • Reported: KerML 1.0b1 — Sun, 3 Dec 2023 02:46 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

SelfLink::thatThing does not exist in Links Model Library

  • Key: KERML-239
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    2nd paragraph, last line
    "end feature thatThing redefines Links::SelfLink::thatThing references f2;"
    SelfLink::thatThing does not exist in ModelLibrary, 9.2.3.2.5 SelfLink, probably referring to SelfLink::sameThing

  • Reported: KerML 1.0b1 — Tue, 21 Nov 2023 21:54 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

PrimaryExpressionMember production should generate a ParameterMembership

  • Key: KERML-61
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    In the BNF in 8.2.5.8.2 Primary Expressions, the PrimaryExpressionMember production is used in BracketExpression, IndexExpression, CollectExpression, SelectExpression and FunctionOperationExpression to parse a PrimaryExpression that is intended to be the initial argument of an InvocationExpression. However, the result of PrimaryExpressionMember is a FeatureMembership that directly owns the parsed PrimaryExpression. But this will not result in the PrimaryExpression being an argument of the containing InvocationExpression because, for that to happen, the Expression needs to be the feature value of a parameter of the InvocationExpression.

    PrimaryExpressionMember should instead be structured like ArgumentMember in 8.2.5.8.1, resulting in a ParameterMembership to a Feature with a FeatureValue relationship to the parsed PrimaryExpression. NonFeatureChainPrimaryExpressionMember also needs to be similarly updated.

  • Reported: KerML 1.0a1 — Wed, 3 May 2023 17:32 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Update semantic model of invariants for validateExpressionResultExpressionMembership constraint

  • Key: KERML-186
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The semantics of an Invariant are given by its implicit specialization of one of two features in the Performances library model: either trueEvaluations or (if the Invariant is negated) falseEvaluations. These features bind the values true and false, respectively, to their result parameter. This gives the Invariant the semantics that, to be consistent, the result expression actually given in the Invariant must evaluate to true or false (respectively).

    The result bindings for trueEvaluations and falseEvaluations are currently specified using ResultExpressionMemberships (to the expressions "true" and "false", respectively). However, the approved resolution to issue KERML-20 included adding the validateExpressionResultExpressionMembership constraint, which requires that an Expression has at most one ResultExpressionMembership among all its memberships, owned and inherited. In a typical Invariant of the form inv {invariantExpression}, the invariantExpression is parsed as being owned by the Invariant via a ResultExpressionMembership. But this now violates the validateExpressionResultExpressionMembership constraint, because it conflicts with the ResultExpressionMembership inherited from trueEvaluations (or falseEvaluations, if the invariant were negated).

  • Reported: KerML 1.0b1 — Sat, 23 Sep 2023 22:27 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Definition of property "typing" seems incomplete/inconsistent

  • Key: KERML-260
  • Status: open  
  • Source: The MathWorks ( Mr. Alan Moore)
  • Summary:

    "typing" seems to be non-navigable owned end of the association between Feature and FeatureTyping.
    However, it is used in a constraint: deriveFeatureType - this seems a little odd.

  • Reported: KerML 1.0b1 — Wed, 20 Dec 2023 10:37 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Typo in Function Abstract Syntax Description

  • Key: KERML-249
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Description
    3rd sentence of 1st (and only) paragraph
    "This calculation may be decomposed into Expressionssteps of the Function."
    The words Expressions and steps have no space between them.
    There are multiple possible resolutions, such as
    "into expressions of"
    "into expression steps of"
    "into steps of"

  • Reported: KerML 1.0b1 — Sun, 3 Dec 2023 03:30 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Typo in Function Declaration Overview

  • Key: KERML-250
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    First paragraph of the page, second sentence
    "A result expression is always be written using the Expression notation described"
    The phrase "expression is always be written" is grammatically incorrect.
    Recommend "expression is always written"
    Although I guess "expression will always be written" is grammatically correct.. I don't think it's tone is consistent with the document's tone

  • Reported: KerML 1.0b1 — Sun, 3 Dec 2023 03:49 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Remove disjointness of LinkObject

  • Key: KERML-251
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    In Objects.kerml, in the declaration of LinkObject:

    abstract assoc struct LinkObject specializes Link, Object disjoint from SelfLink, SelfSameLifeLink, HappensLink
    

    remove disjoint from SelfLink, SelfSameLifeLink, HappensLink.

  • Reported: KerML 1.0b1 — Tue, 19 Dec 2023 19:03 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Some readonly features are intended to have changing values

  • Key: KERML-49
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Read only features (Feature::isReadOnly=true) are described as

    Values of read only features on each instance of their domain are the same during the entire existence of that instance

    but the libraries sometimes apply it to features with values that might be intended to change over the lifetime of an instance. For example, Clause 9.2.12.2.4 (Clock) says

    A Clock provides a scalar currentTime that advances montonically over its lifetime.

    but Clocks::(Basic)Clock::currentTime are readonly:

    Clock { ...
      readonly feature currentTime : NumericalValue[1] {
        doc /* A scalar time reference that advances over the lifetime of the Clock. */ } ... }
    BasicClock { ... readonly feature :>> currentTime : Real; }
    

    Might be others, including features appear at the package level. For example, could check defaultClock, defaultMonitor, and defaultFrame in Clocks.kerml, Observation.kerml, and SpatialFrames.kerml, respectively.

  • Reported: KerML 1.0a1 — Fri, 28 Apr 2023 17:59 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

validateMultiplicityRangeBoundResultTypes constraint is too strong

  • Key: KERML-199
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The validateMultiplicityRangeBoundResultTypes constraint requires "The results of the bound Expression(s) of a MultiplicityRange must be typed by ScalarValues::Natural from the Kernel Data Types Library." However, multiplicity bounds are often given by literals, and the result type of LiteralInteger is actually Integer, which does not conform to Natural.

  • Reported: KerML 1.0b1 — Fri, 20 Oct 2023 13:38 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

LinkObject disjointness is redundant

  • Key: KERML-231
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    The disjointness of LinkObject in Objects.kerml

    abstract assoc struct LinkObject specializes Link, Object disjoint from SelfLink, SelfSameLifeLink, HappensLink
    

    is redundant because SelfSameLifeLink and HappensLink are declared disjoint with Occurrence (a generalization of Object) and SelfLink specializes SelfSameLifeLink in Occurrences.kerml.

  • Reported: KerML 1.0b1 — Wed, 15 Nov 2023 15:34 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Behavior portions must be classified by the same behavior they are portions of

  • Key: KERML-204
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    [Filed for Mr. Raphael Barbau] Clause 9.2.4.1 (Occurrences Overview), under Portions, first paragraph, the last sentence says

    They must be classified the same way as the Occurrences they are portionsOf, or more specialized.

    For a behavior with mandatory steps (features with lower multiplicity>1 typed by behaviors), this means every portion of its performances, including every snapshot, would need to have values for these steps, even when the steps are not intended to happen during/inside of that portion. Likewise for a structure with mandatory parts, eg, like an engine in a car, all spaceslices would need to have this part. The semantic above is not math/modeled.

  • Reported: KerML 1.0b1 — Mon, 23 Oct 2023 17:58 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Specify default direction for the ownedParameterMember of a ParameterMembership

  • Key: KERML-75
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The validateParameterMembershipParameterHasDirection constraint requires that the ownedMemberParameter of a ParameterMembership have a non-null direction – which is what makes it a parameter. However, it does not specify what the direction should be.

    Now, for a ReturnParameterMembership, the validateReturnParameterMembershipParameterHasDirectionOut requires that the direction be out. The validateParameterMembershipParameterHasDirection should be updated so that, for a non-return parameter, the default direction is in.

  • Reported: KerML 1.0a1 — Mon, 8 May 2023 22:31 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Add a property for Annotations owned by an AnnotatingElement

  • Key: KERML-21
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    When parsing the notation for AnnotatingElements that explicitly identify their annotatedElements, the corresponding Annotation relationships are owned by the AnnotatingElement. It would be convenient to have a property that subsets AnnotatingElement::annotation and Element::ownedRelationship that could directly hold these. Note that this cannot be called ownedAnnotations, because AnnotatingElement already inherits a property with that name from Element, which is for Annotations owned by annotated Elements, not AnnotatingElements. Perhaps the new property on AnnotatingElement could be called ownedAnnotatingRelationship.

  • Reported: KerML 1.0a1 — Fri, 21 Apr 2023 22:23 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT
  • Attachments:

Reference to nonexistent class (Superclassification) in OCL rule deriveClassifierOwnedSubclassification

  • Key: KERML-259
  • Status: open  
  • Source: The MathWorks ( Mr. Alan Moore)
  • Summary:

    Comment indicates that this should be Subclassification

  • Reported: KerML 1.0b1 — Wed, 20 Dec 2023 10:17 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Directed features inherited from a conjugated type not handled properly

  • Key: KERML-154
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    Consider the following:

    classifier A {
        in feature f;
    }
    classifier B conjugates A;
    classifier C specializes B;
    

    The feature f is an input of A, but an output of B. However, f will again be considered an input of C, which is not what one would expect.

    The reason for this is that, as currently specified in 8.3.3.1.10 Type, the deriveTypeInput and deriveTypeOutput constraints only flip the inputs and outputs of a type if it is directly conjugated. Otherwise, the derivations just check the direction property of the features of the type, whether they are owned or inherited.

  • Reported: KerML 1.0b1 — Wed, 23 Aug 2023 17:47 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

OclisKindOf applied to Namespace::resolve()

  • Key: KERML-139
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    The definition of Namespace::resolve seems to be missing a memberElement, otherwise namespace will never be a Namespace:

    let namespace : Element = resolve(qualification) in
    if namespace = null or not namespace.oclIsKindOf(Namespace) then null
    else namespace.oclAsType(Namespace).resolveVisible(name) endif
    
  • Reported: KerML 1.0a1 — Thu, 3 Aug 2023 14:16 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Misspelling

  • Key: KERML-161
  • Status: open  
  • Source: Georgia Institute of Technology ( Dr. Richard Wallace)
  • Summary:

    In the EBNF for MetaclassificationExpression:

    MetaclassificationExpression : OperatorExpression =
        ownedRelationship += MetadataArgumentMember
        ( operator = MetaClassificationTestOperator 
          ownedRelationship += TypeReferenceMember
        | operator = MetaCastOperator owendRelationsip += TypeResultMember
    )
    

    The last line should be "ownedRelationshp" and not "owendRelationsip" in the EBNF.

    In the EBNF for IndexExpression:

    IndexExpression : OperatorExpression =
    ownedRelationship += PrimaryExpressionMember
    operator = '#'
    '(' ownedRelationsip += SequenceExpressionListMember ')' 
    

    The last line should be "ownedRelationshp" and not "owendRelationsip" in the EBNF.

  • Reported: KerML 1.0b1 — Tue, 5 Sep 2023 18:35 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

isDirected, definition, semantics

  • Key: KERML-7
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Connector::isDirected is described as

    For a binary Connector, whether or not the Connector should be considered to have a direction from sourceFeature to targetFeature.

    which is circular. There are no other definitions. The semantics is not math/modeled. There is no textual syntax for it. What is intended to express? is it needed?

  • Reported: KerML 1.0a1 — Sat, 15 Apr 2023 14:41 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Follow typographical conventions in the KerML Metamodel clause

  • Key: KERML-23
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    Subclause 8.1 defines typographical conventions to be used in the KerML metamodel. However, these are not being followed consistently throughout Clause 8 and Clause 9.

  • Reported: KerML 1.0a1 — Fri, 21 Apr 2023 22:44 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Name all associations in the KerML abstract syntax

  • Key: KERML-22
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    MOF constraints require that all associations be named. But none of the associations in the KerML abstract syntax model are currently named. They should all be given generated names.

  • Reported: KerML 1.0a1 — Fri, 21 Apr 2023 22:40 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

DataType Disjointness Clarification

  • Key: KERML-174
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    First Sentance of Last Paragraph
    "If any of the types of a feature are data types, then all of them must be."
    This is inconsistent with the Abstract Syntax that does not enforce this constraint, it enforces a weaker constraint.
    Features that are types by DataType can legally be typed by Classifiers according to 8.4.4.2 semantics
    8.4.4.2 Data Types Semantics states that DataType is disjoint with Class and Association,
    so a more consistent statement would be that then
    "If any of the types of a feature are DataTypes, then it can't also be typed by Class or Associations.

  • Reported: KerML 1.0b1 — Sat, 16 Sep 2023 18:22 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Exponentiation should be right-associative

  • Key: KERML-165
  • Status: open  
  • Source: Dassault Systemes ( Mr. Andrius Armonas)
  • Summary:

    If you look at the following sample:

    1 a = 2 ^ 3 ^ 4;
    2 a = (2 ^ 3) ^ 4;
    3 a = 2 ^ (3 ^ 4);

    Both lines 1 and 2 will generate the same model in SysML v2 pilot implementation.
    This means that exponentiation operator seems to be left-associative, which is unusual, as exponentiation is supposed to be right-associative.

  • Reported: KerML 1.0b1 — Thu, 14 Sep 2023 15:06 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Features successors and predecessors of Occurrence should be disjoint

  • Key: KERML-234
  • Status: open  
  • Source: Budapest University of Technology and Economics ( Dr. Vince Molnar)
  • Summary:

    Features successors and predecessors of Occurrence should be disjoint. Otherwise, the library would allow circular HappensBefore graphs. If HappensBefore is to be interpreted as a strict temporal ordering constraint (which is suggested by the current documentation in the library) or is supposed to capture causality relationships, such cycles could/should not be collapsed into time-coincident occurrences, always leading to unsatisfiable models.

  • Reported: KerML 1.0a1 — Sat, 25 Nov 2023 11:30 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Measuring devices for space missing

  • Key: KERML-282
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    KerML provides measuring devices for time (clocks), but not space ("measuring rods").

  • Reported: KerML 1.0b1 — Thu, 21 Dec 2023 17:02 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

User-defined keywords are not allowed on metadata features

  • Key: KERML-307
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The production MetadataFeature in 8.2.5.12 Metadata Concrete Syntax does not provide for the use of user-defined keywords, even though nested metadata feature annotations are allowed. (Note that the production Metaclass does allow user-defined keywords to be used on metaclass definitions.)

  • Reported: KerML 1.0b1 — Tue, 2 Jan 2024 19:53 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

package "Interactions TBD" should not be included in the XMI file

  • Key: KERML-309
  • Status: open  
  • Source: The MathWorks ( Mr. Alan Moore)
  • Summary:

    Package Interactions TBD should not be included in the KerML.xmi file.

  • Reported: KerML 1.0b1 — Fri, 12 Jan 2024 18:01 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

LinkObject is irreflexive

  • Key: KERML-45
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    The libraries have LinkObject disjoint with SelfLink, which classifies all links that have the same thing at both ends, preventing LinkObject from linking things to themselves.

  • Reported: KerML 1.0a1 — Thu, 27 Apr 2023 18:58 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

FlowTransferBefore needs end feature declarations

  • Key: KERML-120
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The interaction FlowTransferBefore in the Transfers library package specializes both FlowTransfer and TransferBefore. Both FlowTransfer and TransferBefore are binary, so FlowTransferBefore has to be, too. However, in the normative Transfers.kerml file from the Kernel Semantic Library project, FlowTransferBefore is currently declared without owned end features, so it inherits two ends each from FlowTransfer and TransferBefore, for a total of four, which is incorrect. Instead, it needs to declare two nested end features that redefine the corresponding ends from each of the interactions it specializes.

    (Note that, in subclause 9.2.7.2.3 of the specification document, FlowTransferBefore is actually documented as properly having two owned ends.)

  • Reported: KerML 1.0b1 — Wed, 12 Jul 2023 21:35 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

checkConnectorTypeFeaturing is not correct

  • Key: KERML-82
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    The OCL for the checkConnectorTypeFeaturing constraint (see 8.3.4.5.3) uses the Feature::isFeatureWithin operation (see 8.3.3.3.3) to check that each relatedFeature of a Connector is "within" a featuringType of the Connector. Unfortunately, isFeatureWithin is currently specified to allow "downward nesting" of a Feature. For example, in the following:

    classifier A {
        feature x;
        feature y {
            feature z;
        }
        connector c from x to y::z;
    }
    

    the Feature z is considered to be indirectly "featured within" the Classifier A. But this means that the Connector c is then considered to be valid, which it shouldn't be – a feature chain y.z should be required to be used instead of the qualified name y::z.

  • Reported: KerML 1.0a1 — Sat, 13 May 2023 23:11 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Comment Locale not in textual notation

  • Key: KERML-98
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    8.3.2.3.4 Comment Attributes shows a locale, but it can't be accessed through the 8.2.3.3.2 declared textual notation

  • Reported: KerML 1.0b1 — Sun, 9 Jul 2023 20:14 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Disjoining example conflicts with textual description

  • Key: KERML-110
  • Status: open  
  • Source: Self ( Jim Ciarcia)
  • Summary:

    Third Paragraph

    disjoining disjoint Person::parents from Person::children {
    	doc /* No Person can be their own parent. */
    }
    

    The documentation does not reflect the actual disjoining being performed.
    The disjoin separates a person's parents set from that person's children set.
    Thus the disjoin is not about the person himself
    Either fix the documentation to say "A person's parents can't also be their children, and visa versa."
    or fix the disjoining
    disjoining disjoint Person::self from Person::parents

  • Reported: KerML 1.0b1 — Sun, 9 Jul 2023 23:11 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

specializesFromLibrary arguments use inconsistent notation for strings

  • Key: KERML-125
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    The arguments for specializesFromLibrary are sometimes single quoted and sometimes double quoted. Search on specializesFromLibrary(' and specializesFromLibrary(" to find them.

  • Reported: KerML 1.0a1 — Sun, 30 Jul 2023 13:22 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT

Intersection missing for some multiple specializations

  • Key: KERML-46
  • Status: open  
  • Source: NIST ( Mr. Conrad Bock)
  • Summary:

    Some multiple specializations in the libraries might be intended to be intersections, including feature specializations. For example, quite a few in Performances.kerml:

    step subperformances: Performance[0..*] subsets performances, suboccurrences;
    expr subevaluations: Evaluation[0..*] subsets evaluations, subperformances;
    step subtransfers: Transfers::Transfer[0..*] subsets transfers, subperformances;
    step subtransfersBefore: Transfers::TransferBefore[0..*] subsets transfersBefore, subtransfers;
    

    In Links.kerml:

    assoc struct LinkObject specializes Link, Object ... { ... }
    assoc struct BinaryLinkObject specializes BinaryLink, LinkObject {... }
    

    Might be others. Sometimes this is modeled with sufficiency, for example in Occurrences::Occurrence::

    feature all spaceTimeEnclosedOccurrences: Occurrence[1..*] subsets timeEnclosedOccurrences, spaceEnclosedOccurrences { ... }
    feature all spaceTimeEnclosedPoints : Occurrence[1..*] subsets spaceTimeEnclosedOccurrences { ... }
    

    If sufficiency isn't needed for other reasons, it could be replaced with intersection.

  • Reported: KerML 1.0a1 — Fri, 28 Apr 2023 14:35 GMT
  • Updated: Mon, 8 Apr 2024 21:42 GMT