The Implementation of Polymorphic Many-Dorted Type System for Logic Programming Language Gödel

Gödel is a declarative logic programming language succeeded to prolog. One of its important characteristics is polymorphic many-sorted type system. In this paper, we first introduce a notion of typed first order language. Then give the definitions of types and type expression for the polymorphic type system. And we provide the data structures and algorithms for implementing polymorphic many-sorted types checking, dynamic type matching and type inference. The coral implementation techniques of Gödel compiler related to polymorphic many-sorted types are also represented.