PM-STA-0040

An Operation MUST declare exactly one State as the State it achieves. An implementation MUST NOT permit an Operation to name zero or several achieved States, except for the grouping Operations that exist only to parent a taxonomy and achieve none.

Non-normative, and it does useful work against PM-STR-0030. Even where state() returns a set because several Restrictions overlap, the transition is single-valued: the Operation names its target. So the ambiguity is in classification, not in the transition function, which is a materially smaller problem than "the method is non-deterministic" suggests. The determinism defect is about which State an object is reported to be in, not about where a transition goes.