SysML 2.0b2 FTF Avatar
  1. OMG Issue

SYSML2 — Semantics of a conditional succession using "else" are missing

  • Key: SYSML2-100
  • Status: open  
  • Source: Model Driven Solutions ( Mr. Ed Seidewitz)
  • Summary:

    In 7.16.5 Conditional Successions, in the second paragraph, it states:

    Further, the keyword else may be used in place of a guard expression to indicate a succession to be taken if the guards evaluate to false on all of an immediately preceding set of conditional successions.

    In, a conditional succession with the else keyword is parsed as a TransitionUsage that simply does not have a guard condition:

    DefaultTargetSuccession : TransitionUsage =
        'else' ownedRelationship += TransitionSuccessionMember

    However, the semantics of such a TransitionUsage would seem to be that it can be taken unconditionally, not that it can only be taken if preceding conditional successions have guards that evaluate to false. The else case is not mentioned at all in Decision Transition Usages, which covers the semantics of conditional successions.

  • Reported: SysML 2.0a1 — Fri, 28 Apr 2023 22:10 GMT
  • Updated: Wed, 10 Apr 2024 00:41 GMT