UTP12 — Correction for issue #15652

This is a correction for issue #15652:

In the resolution for issue #15652 we restricted the number of <<TestComponent>> lifelines that are covered by a <<DetermAlt>> to one.

This is too restrictive. There can be of course several test component lifelines being covered by the very same <<DetermAlt>>.

Possible resolution:
Remove the first paragraph in the semantics section

Change the first sentence of the current second paragraph from

If a deterministic alternative is reached during the execution of an interaction, the involved test component waits until it receives an input

to

If a deterministic alternative is reached during the execution of an interaction, the involved test component lifeline waits until it receives an input

• Remove constraint [2]

The way UTP 1.1 has refined or clarified the ‘determAlt’ ended up in a description identical to TTCN-3, the language where the ’determAlt’ concept was taken over from. The fact that the equivalent altsteps (in TTCN-3) are applied to each test component separately should not influence the way how this concept has to be applied in UTP. UTP should rather abstract from a concrete technical implementation and describe the concept according to the possibilities or semantics of UML Interactions.
In short, the resolution partially takes over what the issue submitter said, i.e. that more than one test component can be covered by a CombinedFragment with «determAlt» applied. Furthermore, some typos and misspellings will be corrected.