The Houria Constraint Solver

The Houria constraint solver is an efficient incremental algorithm that uses local propagation to maintain sets of required and preferential constraints. Houria represents constraints between variables by sets of short procedures (methods) and incrementally resatisftes the set of constraints when individual constraints are added and removed. The criterion of comparison used in Houria is more powerful than that of some other solvers. Houria is used to construct a graph of methods by planning and executing all these methods to found a best solution. The solution found by Houria satisfies more constraints than the one produced by some other solvers and that for the same over-constrained problems while respecting the hierarchy.