Functional unification of higher-order patterns

Abstract

The complete development of a unification algorithm for so-called higher-order patterns, a subclass of lambda -terms, is presented. The starting point is a formulation of unification by transformation, and the result a directly executable functional program. In a final development step, the result is adapted to lambda -terms in de Bruijn's (1972) notation. The algorithms work for both simply typed and untyped terms. >