Transformation Rules for Logic Programs with Goals as Arguments

Abstract

AbstractWe introduce a logic language where predicate symbols may have both terms and goals as arguments. We define its operational semantics by extending SLD-resolution with the leftmost selection rule, and we propose a set of transformation rules for manipulating programs written in that language. These transformation rules are shown to be correct in the sense that they preserve the chosen operational semantics. This logic language has higher order capabilities which turn out to be very powerful for the derivation of efficient logic programs. In particular, in our language we can avoid the problem of goal rearrangement which is often encountered during program transformation. Moreover, goals as arguments allow us to perform on logic programs transformation steps similar to the ones performed on functional programs when using higher order generalizations and continuation arguments.KeywordsLogic ProgramTransformation RuleOperational SemanticPredicate SymbolLogic LanguageThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.