We present a term rewriting procedure based on congruence closure that can be used with arbitrary equational theories. This procedure is motivated by the pragmatic need to prove equations in equational theories where ...

It is obvious to anyone familiar with the rules of the game of chess that a king on an empty board can reach every square. It is true, but not obvious, that a knight can reach every square. Why is the first fact obvious ...

We consider the concept of local sets of inference rules. Locality is a syntactic condition on rule sets which guarantees that the inference relation defined by those rules is polynomial time decidable. Unfortunately, ...