OCL25 — OclUndefined / allInstances() clarification.

think the operation allInstances() is under-specified in the current version of the OCL 2.0 specification.

It does not seem to be clear whether OclUndefined is included in the returned set or not:

According to the 1.5 specification of allInstances(), the instances of all subtypes are included. OclVoid is a subtype of all other types, thus OclUndefined would be a part of the set.

I assume this is not the intended behaviour. For example, the "all names must be different" expression example would always yield OclUndefined or false, but never true.