Semantics for Prolog via term rewrite systems -- Hierarchical contextual rewriting with several levels -- Confluence of conditional rewrite systems -- Solving goals in equational languages -- On the use of conditional rewrite rules in inductive theorem proving -- A completion procedure for conditional equations -- A compiler for a class of conditional term rewriting systems -- Notes on the elimination of conditions -- Equational axiomatizations of if-then-else -- Compiling conditional rewriting systems -- Positive/negative conditional rewriting -- On word problems in Horn theories -- Conditional specifications with inequational assumptions -- A logical analysis on theory of conditional rewriting -- Computing with conditional rewrite rules -- A logic for conditional term rewriting systems -- Confluent term rewriting systems with membership conditions -- TRSPEC: A term rewriting based system for algebraic specifications -- CEC: A system for the completion of conditional equational specifications -- Asspegique -- REVEUR4: A laboratory for conditional rewriting -- An introduction to OBJ 3 -- The Passau RAP system: Rapid prototyping for algebraic specifications -- Architecture for conditional term rewriting.

The 1st International Workshop on Conditional Term Rewriting Systems took place in Orsay (University of Paris-Sud) in July 1987, and brought together most of the researchers involved in the field. Conditional rewriting has actually known important breakthroughs during the last two years; it was the purpose of the workshop to put the results together, to present new, original contributions to the domain, and to discuss still unsolved issues. These contributions are reported in the proceedings. The main questions that have been addressed are the different semantics for conditional rewriting and their classification, possible extensions to the basic formalism, and the relationship between conditional rewriting and logic programming. Also, more practical issues such as applications and implementations of conditional term rewriting systems have been addressed. Descriptions of seven actual systems allowing conditional rewriting are included.