User's Functions in Standard Prolog

We integrate user-defined functions with semantic equations into standard Prolog. In order to interface them with Prolog, we introduce a single operator. If a predicate invocation is prefixed by this operator, its parameters are expressions evaluated by the standard arithmetic of Prolog, and by our equations using innermost basic narrowing. The extended language is called PLN 5. (PLN = ProLog with Narrowing). PLN 5 conforms to the ISO standard of Prolog without compromise. It is a simple but flexible, conservative functional extension of ISO Prolog. It does not introduce runtime overhead, and it avoids error-prone constructs. It adds the expressiveness of functions to the notational power of Prolog. PLN 5 is implemented in a SICStus Prolog module, and it is fully integrated with this host language. The implementation depends on the term- and goal-expansion capabilities of SICStus.

• Type: Conference
• Year: 2003
• Where: SPLST
• Authors: Tibor Ásványi
• Keywords: Programming Languages, Prolog, SICStus Prolog Module, SPLST 2003, Standard Prolog