A Generic Scheme for Qualified Constraint Functional Logic Progamming

TL;DR

This paper introduces a more expressive language for qualified constraint functional logic programming, using rewriting logic and program transformation, with applications in flexible information retrieval like library queries.

Contribution

It presents a new language framework with a semantic characterization and prototype implementation for qualified constraint functional logic programming.

Findings

Semantic correctness of the program transformation

Prototype implementation demonstrating feasibility

Application example in library book queries

Abstract

Qualification has been recently introduced as a generalization of uncertainty in the field of Logic Programming. In this report we investigate a more expressive language for First-Order Functional Logic Programming with Constraints and Qualification. We present a Rewriting Logic which characterizes the intended semantics of programs, and a prototype implementation based on a semantically correct program transformation. Potential applications of the resulting language include flexible information retrieval. As a concrete illustration, we show how to write program rules to compute qualified answers for user queries concerning the books available in a given library.