Incremental evaluation of natural semantics specifications

Abstract

Natural Semantics is a logical formalism used to specify semantic aspects of a language by sets of logical rules (called a Typol program) where a query is proved using Prolog. In a previous paper, we have shown how to replace, under certain hypotheses, the Prolog engine by a functional evaluator; this is possible because unification is no longer required and can be replaced by pattern matching. Starting from this previous work, we now add incremental facilities to our evaluator. That is to say, after some modification of a term whose semantic value has already been evaluated, we do not need to re-evaluate everything from scratch as it is the case with a Prolog engine.