SYSPHS12 — Suggest explicitly support the Modelica when/then statement

Modelica 'when/then' statements are not explicitly listed under SysPhS-1.1 8 Language for Mathematical Expressions on p.9, which states that:

The SysPhS expression grammar includes a subset of Modelica’s grammar ...

The MagicDraw/Cameo tool v19SP3 does not cleanly export when/then statements used in Constraints.

The Modelica when/then statement is very widely used in practical problems, and is in most cases not replaceable by if/then/else statements. For example, many of the Modelica By Example studies involve when/then statements:

https://mbe.modelica.university/behavior/discrete/when/

StableBouncingBall under: https://mbe.modelica.university/behavior/discrete/bouncing/

SampleAndHold, IntervalMeasure, Counter, and CounterWithAlgorithm under: https://mbe.modelica.university/behavior/discrete/measuring/

HysteresisControlWithAlgorithms under: https://mbe.modelica.university/behavior/discrete/hysteresis/#hysteresis