SMOF_ — CompatibleWith/IncompatibleWith and the Law of the Excluded Middle

It is unclear what what relationship to deduce between a pair classifiers where neither "CompatibleWith" nor "IncompatibleWith" has been asserted between them. Is the default assumption that they are compatible, not compatible, or that there is no information?

The description of "CompatibleWith" (11.2.2) says:

" ... if AspectOf or CompatibleWith does not exist between two classes (or their supertypes) an instance may not be explicitly classified by both classes ..."

What is the meaning of "may" in that sentence? If the intended meaning is "shall", then it's clear that in the absence of CompatibleWith between two classes, those two classes are not compatible. However, if the intended meaning is indeed "may/might", then the the sentence does nothing to remove the ambiguity.

It is also unclear what behaviour is intended if both CompatibleWith and IncompatibleWith exist between the same pair of classifiers. Presumably this is an error, but how exactly shall a compliant implementation behave under these circumstances?

The semantic issue regarding Compatibility is addressed by the resolution to issue 17150; the issue raised against the Profile (clause 11) has no effect, as the Profile has been removed from the specification.
Revised Text:
No change.
Disposition: Closed – Duplicate / Merged – see issue 17163