Rewriting Techniques and Applications: 4th International Conference, RTA-91, Como, Italy, April 10-12, 1991. Proceedings

Transfinite reductions in orthogonal term rewriting systems.- Redex capturing in term graph rewriting (concise version).- Rewriting, and equational unification: the higher-order cases.- Adding algebraic rewriting to the untyped lambda calculus (extended abstract).- Incremental termination proofs and the length of derivations.- Time bounded rewrite systems and termination proofs by generalized embedding.- Detecting redundant narrowing derivations by the LSE-SL reducibility test.- Unification, weak unification, upper bound, lower bound, and generalization problems.- AC unification through order-sorted AC1 unification.- Narrowing directed by a graph of terms.- Adding homomorphisms to commutative/monoidal theories or how algebra can help in equational unification.- Undecidable properties of syntactic theories.- Goal directed strategies for paramodulation.- Minimal solutions of linear diophantine systems : bounds and algorithms.- Proofs in parameterized specifications.- Completeness of combinations of constructor systems.- Modular higher-order E-unification.- On confluence for weakly normalizing systems.- Program transformation and rewriting.- An efficient representation of arithmetic for term rewriting.- Query optimization using rewrite rules.- Boolean algebra admits no convergent term rewriting system.- Decidability of confluence and termination of monadic term rewriting systems.- Bottom-up tree pushdown automata and rewrite systems.- On relationship between term rewriting systems and regular tree languages.- The equivalence of boundary and confluent graph grammars on graph languages of bounded degree.- Left-to-right tree pattern matching.- Incremental techniques for efficient normalization of nonlinear rewrite systems.- On fairness of completion-based theorem proving strategies.- Proving equational and inductive theorems by completion and embedding techniques.- Divergence phenomena during completion.- Simulating Buchberger's algorithm by Knuth-Bendix completion.- On proving properties of completion strategies.- On ground AC-completion.- Any ground associative-commutative theory has a finite canonical system.- A narrowing-based theorem prover.- ANIGRAF: An interactive system for the animation of graph rewriting systems with priorities.- Emmy: A refutational theorem prover for first-order logic with equations.- The tecton proof system.- Open problems in rewriting.