Applications of recursion in higher types to the semantics of natural 
language.

Yiannis Moschovakis

   The "translation" of fragments of English into the typed lambda-calculus 
initiated by Montague around 1970 makes (rather surprisingly) higher-type 
recursion relevant to the study of semantics of natural languages. I will 
discuss a technical result which can be interpreted as establishing the 
"decidability of synonymy" (for the fragments of English to which it applies), 
as well as some conclusions which can be drawn from it about plausible 
semantics for "propositional attitudes", like "knowledge" and "belief".