Generative Constraint Programming Revisited

Around twenty years ago, Generative Constraint Programming techniques, such as the Generative Constraint Satisfaction Problem (GCSP), were developed to deal with problems mainly based on functional constraints or relaxation of such constraints, like the ones in industrial configuration problems. In 2023, we introduced On-the-fly Constraint Programming Search (OTFS), inspired by GCSP, to successfully tackle Model Checking problems that have a lot of functional constraints. This paper aims to show that a revised version of OTFS, called GenCP, can also be used on classical textbook CP problems that do not involve constraints resembling functional constraints: the NQueens and All-Interval problems, and two lesser known CP problems, Graceful Graphs and Langford Number. GenCP significantly reduces execution times on these problems, showing that it is a valid alternative to traditional CP.