A Mathematical Definition of Full Prolog

The paper provides a mathematical yet simple model for the full programming language Prolog, as apparently intended by the ISO draft standard proposal. The model includes all control constructs, database operations, solution collecting predicates and error handling facilities, typically ignored by previous theoretical treatments of the language. We add to this the ubiquitous box-model debugger. The model directly reeects the basic intuitions underlying the language and can be used as a primary mathematical deenition of Prolog. The core of the model has been applied for mathematical analysis of implementations, for clariication of disputable language features and for specifying extensions of the language in various directions. The model may provide guidance for extending the established theory of logic programming to the extralogical features of Prolog.