Isomorphisms of Types

Isomorphisms of types is a research topic in type theory that has valuable practical applications both for programming language design and for more human-centred information retrieval in software libraries. By means of a study into the syntax of the now widely known typed lambda-calculus, it is possible to identify some simple equations between types that on one hand can improve the design of the ML language, and on the other hand provide the basis for building radically new information retrieval systems for functional software libraries. In this book the author presents the theoretical aspects of this research.