SYSML17 — Refine / Trace relationship operations are too restrictive

Refine::getRefines(in ref : NamedElement) : AbstractRequirement should return NamedElement according to the definition of the refine stereotype in section 16.1. The body condition of the operation is not consistent with the return type AbstractRequirement.

There is no constraint that restricts that one end of the refine relationship must be an element of type AbstractRequirement.

Trace::getTracedFrom(in ref: NamedElement) : AbstractRequirement should return NamedElement according to the definition of the trace stereotype. The body condition should be updated as well from AbstractRequirement to NamedElement.

The sentence in section 16.1 "A generic trace requirement relationship provides a general-purpose relationship between a requirement and any
other model element." is too restrictive with regard to the definition of the trace stereotype.