SYSML2_ — Inconsistent and/or incomplete graphical notation for standard reference-subsetted usages

In subclause 7.20.1, Table 19, example "Requirement" the compartment labels "require constraints" and "assume constraints" and their content are misleading and inconsistent. Besides pure "require ConstraintUsage" statements a "require constraints" compartment may also contain "require RequirementUsage" statements. A "require RequirementUsage" has the same semantics as a RequirementUsage contained (isComposite==true) by a containing RequirementUsage (see explanation in subclause 7.20.2). Therefore a better compartment name is possibly "requires".

The same problem applies to other compartments for shorthand textual notation for particular reference-subsetted usages following a similar pattern. The full list of patterns to be made consistent is:

• assert (constraint)
• assume (constraint)
• exhibit (state)
• frame (concern)
• include use case
• perform (action)
• require (constraint)
• satisfy (requirement)
• verify (requirement)

In addition a mix of verb forms are used: some use the infinitive (exhibit states, satisfy requirements), some use third person singular form (exhibits, satisfies). This is confusing and should be regularized in a consistent way, following a single rule.

Finally, graphical edges that represent the above reference-subsetted relationships between usage nodes are inconsistently specified in the representative notation tables in clause 7, and the graphical BNF in subclause 8.2.3.