An automated technique to translate conditional rewrite rules into unconditional ones is presented, which is suitable to implement, or compile, conditional rewriting on top of much simpler and easier to optimize unconditional rewrite systems. An experiment performed on world’s fastest conditional rewriting engines shows that speedups for conditional rewriting of an order of magnitude can alread...

Constraints on Pseudo-Boolean (PB) expressions can be translated into Conjunctive Normal Form (CNF) using several known translations. In Answer-Set Programming (ASP), analogous expressions appear in weight rules and optimization statements. Previously, we have translated weight rules into normal rules, using normalizations designed in accord with existing CNF encodings. In this work, we rededic...

ELAN is a powerful language and environment for specifying and prototyping deduction systems in a language based on rewrite rules controlled by strategies. It offers a natural and simple logical framework for the combination of the computation and deduction paradigms. It supports the design of theorem provers, logic programming languages, constraint solvers and decision procedures. ELAN takes f...

We present a survey of connuence properties of (acyclic) term graph rewriting. Results and counterexamples are given for diierent kinds of term graph rewriting: besides plain applications of rewrite rules, extensions with the operations of collapsing and copying, and with both operations together are considered. Collapsing and copying together constitute bisimilarity of term graphs. We establis...

A nite string-rewriting system R preserves regularity if and only if it preserves-regularity, where is the alphabet containing exactly those letters that have occurrences in the rules of R. This proves a conjecture of Gyenizse and VV agvv olgyi (1995). In addition, some undecidability results are presented that generalize some results of Gilleron and Ti-son (1995) from term-rewriting systems to...

The direct sum of two term rewriting systems is the union of systems having disjoint sets of function symbols. It is shown that the direct sum of two term rewriting systems is not terminating, even if these systems are both terminating. Keyword: Term rewriting system, termination Introduction A term rewriting system R is a set of rewriting rules M → N , where M and N are terms [1, 3, 5]. The di...

We introduce a notion of bisimulation for graph rewriting systems, allowing us to prove observational equivalence for dynamically evolving graphs and networks. We use the framework of synchronized graph rewriting with mobility which we describe in two different, but operationally equivalent ways: on graphs defined as syntactic judgements and by using tile logic. One of the main results of the p...

In this paper we outline the use of term rewriting techniques for modeling the dynamic behavior of Web sites. We associate rewrite rules to each Web page expressing the Web pages which are immediately reachable from this page. The obtained system permits the application of well-known results from the rewriting theory to analyse interesting properties of the Web site. In particular, we briefly d...