Update Propagation Network - A Framework for Constraint Programming

As a framework for constraint programming, a Network model named CellR while the former is generating a hypothesis dynamically, the latter evaluates it and controls the propagation. Some heuristics are incorporated to localize the effects of the propagation. An extension to Prolog, named Constraint Prolog, is also included to deal with hypothetical reasoning and lazy evaluation. Constraint Prolog is the interpreter of the update propagation mechanism.