Montague's linguistic theory provides a completely formalized account of language in general and natural language in particular. It would appear to be especially applicable to the problem of natural language understanding by computer systems. However the theory does not deal with meaning at the lexical level. As a result, deduction in a system based on Montague semantics is severely restricted. This paper considers lexical extension of Montague semantics as a way to remove this restriction. Representation of lexical semantics by a logic program or semantic net is complex. An alternative representation, called a semantic space, is described. This alternative lacks the expressiveness of a logic program but it offers conceptual simplicity and intrinsically parallel structure.
Purdy, William C., "A Lexical Extension of Montague Semantics" (1988). Electrical Engineering and Computer Science Technical Reports. 30.