A Wam Implementation for Flexible Query Answering1

In [7] Maria I. Sessa extended the SLD resolution principle with the ability of performing approximate reasoning and flexible query answering. The operational mechanism of similarity-based SLD resolution can be used as the basis for a new logic language that allows to manage uncertain and imprecise information in a declarative framework, hence its importance. Similarity-based SLD resolution can be seen as an extension of the classical SLD resolution procedure where the syntactic unification algorithm has been replaced by a fuzzy unification algorithm. In this paper we address the problem of adapting the implementation of a WAM to incorporate fuzzy unification. As a result, we obtain a Prolog implementation based on similarity relations that we call S-Prolog. To the best of our knowledge this is the first WAM implementation that supports similarity-based SLD resolution.