Termination is a major question in both logic and computer science. In logic, termination is at the heart of proof theory where it is usually called strong normalization (of cut elimination). In computer science, termination has always been an important issue for showing programs correct.

Abstract. In contrast to the current general way of developing tools for proving termination automatically, this paper intends to show an alternative program based on using on the one hand the theory of term orderings to develop powerful and widely applicable methods and on the other hand constraint based techniques to put them in practice. In order to show that this program is realizable a constraint-based framework is presented where ordering based methods for term rewriting, including extensions like Associative-Commutative rewriting, Context-Sensitive rewriting or Higher-Order rewriting, as well as the use of rewriting strategies, can be put in practice in a natural way. 1

There is an increasing use of (first- and higher-order) rewrite rules in many programming languages and logical systems. The recursive path ordering (RPO) is a well-known tool for proving termination of such rewrite rules in the first-order case. However, RPO has some weaknesses.

Abstract. Many functional programs and higher order term rewrite systems contain, besides higher order rules, also a significant first order part. We discuss how an automatic termination prover can split a rewrite system into a first order and a higher order part. The results are applicable to all common styles of higher order rewriting with simple types, although some dependency pair approach is needed to use them. Key words: higher order rewriting, termination, dependency pairs, modularity 1