Techniques for Implementing Contexts in Logic Programming

In this paper we discuss different techniques for implementing an extension of logic programming for knowledge structuring. The extension we consider, in particular, is based on Contextual Logic Programming. Three different implementation approaches are considered first: meta-interpretation, translation into Prolog code and compilation on an extended Warren Abstract Machine. These approaches are compared from the point of view of both methodology and efficiency. In the last part of the paper we consider a more effective implementation, developed on an industrial Prolog enhanced with the module construct.