Integrating Interval Constraints into Logic Programming
This work provides a logic semantics for efficient floating-point hardware, addressing the practical need in scheduling and engineering design to handle numerous CSPs efficiently.
The paper introduces CLP/NCSP, a new subscheme of CLP that integrates interval constraints into logic programming, enabling efficient solving or proving unsolvability of thousands of constraint satisfaction problems for scheduling and engineering design.
The CLP scheme uses Horn clauses and SLD resolution to generate multiple constraint satisfaction problems (CSPs). The possible CSPs include rational trees (giving Prolog) and numerical algorithms for solving linear equations and linear programs (giving CLP(R)). In this paper we develop a form of CSP for interval constraints. In this way one obtains a logic semantics for the efficient floating-point hardware that is available on most computers. The need for the method arises because in the practice of scheduling and engineering design it is not enough to solve a single CSP. Ideally one should be able to consider thousands of CSPs and efficiently solve them or show them to be unsolvable. This is what CLP/NCSP, the new subscheme of CLP described in this paper is designed to do.