OCL25 — Issue: Grammar of OCL

Description: The grammar presented in 4.3, which is in my opinion a semantic grammar, is not suitable to describe the syntax of OCL.
Rationale: Introducing non-terminals like primary-expression, selection-expression, and operation-call-expression will solve all the problems and will reduce the number of ambiguities. Hence, the grammar contained in the specification will suffer less changes in order to be used to design and implement a deterministic parser. This is the case of the specifications for C, C++, Java, C#, and Prolog.