But, you can do the same thing with a couple lines of Prolog. You can also write a "perfect" chess program in Pascal, but it will take forever to make its first move.

There are systems that do constraint-based programming, such as Trilogy, Prolog, and CLP. When used correctly, it's no slower than the code you'd have to write to solve the problem anyway.

I agree that this module is too slow for anything significant, in terms of modeling solutions based on that kind of logic. I suppose it's exactly what you want if you are in fact writing programs for quantum mechanical physics work. But, call it a proof-of-concept of Entanglement of variables.

—John