SYSML16 — Problems with property-specific types

Definition of a property-specific type cannot be shown on a bdd. This would require, at least, a defined name for the block or value type that types the property, such as one based on the property name.

No runtime semantics is given. Presumably all instances of a property-specific type are values of the property it types, but this isn't said anywhere. It the property it types is an end of an association, this could be expressed by a lower multiplicity greater than zero on opposite end.

No examples of property specific types are given.

CB, 2018-05-03: Address interaction with property subsetting/redefinition. For example redefinition that doesn't change the PST will cause it to be owned twice, because is repeated in the redefining property.

The requirements for property-specific types to be anonymous, singly generalized, and owned by the owner of the property they type don't appear to be necessary. Naming is useful for managing PSTs, multiple generalization is useful for reusing property defaults and other characteristics on multiple PSTs, and package ownership enables the same PST to be used on multiple properties that have the same type.

The description of the property-specific types refers to:

"local specializations of referenced typed" (Section 8.3.1.1 Block Definition Diagram) and

"starting classifier of the property-specific type." (Section 8.3.2.7 PropertySpecificType)

The terms "local", "referenced type", "starting classifier nof the property specific type" are undefined and not deducible from other text.

The following sentence is a tautology (ie, adds nothing to the spec):

"The PropertySpecificType stereotype is automatically applied to the "classifier that types a property with a propertyspecific type. (Section "8.3.2.7 PropertySpecificType)"

because a property with a property specific type is one where the property type has the PropertySpecificType applied.

Section 8.3.1.1 (Block Definition Diagram) at the end says the name of the property specific type can be included in brackets, but constraint [2] of PropertySpecificType says they are anonymous.

The discussion of compartments on internal properties in Section 8.3.1.2 (Internal Block Diagram) can be simplified by removing the discussion of property-specific types.

PST clarifications, minor corrections

The purpose of this resolution is to clarify the semantics of the PropertySpecificType stereotype and to fix minor issues with its current description