Global computing by networked equational constraint solvers

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We worked on the design and implementation of an open system for collaborative constraint solving. The outcome of our efforts is a system called Open CFLP, which provides support for collaborative constraint functional logic programming in open environments. The system provides support for(a) higher-order functional logic programming over constraint domains equipped with specialized solvers. Reasoning over functional logic programs is realized by specialized solvers based on higher-order lazy narrowing calculi ;(b) transparent access to specialized constraint solvers via the lookup service of a specialized broker ;c a collaboration language which enables the user to specify the most common ways in which constraint solvers should collaborate to achieve the desired results.For (a), we have designed and implemented in Mathematica various refinements of higher-order lazy narrowing which are relevant for programming purposes. These refinements are very important because they reduce the huge search space for solutions. For (b), we have designed and implemented a lookup service that allows transparent access to constraint solvers advertised by providers in an open environment such as the Internet. The user asks for a solver characterized by a certain interface and attributes (e.g., constraint solving domain, solving method, etc.) and the lookup service yields a proxy to such a remote solver (if available). For c, we have designed and implemented a solver collaboration language which provides primitives to describe the most common ways to combine component solvers into a higher-level constraint solving procedure.