Congruential complements of ground term rewrite systems

Deciding Confluence of Ground Term Rewrite Systems in Cubic Time

It is well known that the confluence property of ground term rewrite systems (ground TRSs) is decidable in polynomial time. For an efficient implementation, the degree of this polynomial is of great interest. The best complexity bound in the literature is given by Comon, Godoy and Nieuwenhuis (2001), who describe an O(n5) algorithm, where n is the size of the ground TRS. In this paper we improv...

Non-connuent Term-rewrite Systems

The transfer component of a machine translation (MT) system typically comprises three aspects, namely the transfer structure used to transfer source into target structures, the (set of) transfer rules and the transfer process, which interpretes the set of transfer rules to derive the target from the source structure. The transfer structure can be formally considered as a term and the set of tra...

Productivity of Non-Orthogonal Term Rewrite Systems

Productivity is the property that finite prefixes of an infinite constructor term can be computed using a given term rewrite system. Hitherto, productivity has only been considered for orthogonal systems, where non-determinism is not allowed. This paper presents techniques to also prove productivity of non-orthogonal term rewrite systems. For such systems, it is desired that one does not have t...

Transformations of Conditional Term Rewrite Systems

Term rewriting is a well understood and commonly used framework in theoretical computer science for program analysis and program verification. An intuitive extension of term rewrite systems are conditional term rewrite systems. Yet, although they are more natural for certain tasks, they turn out to be more complex to analyze. In order to better understand and implement conditional term rewrite ...

Automated Complexity Analysis of Term Rewrite Systems