WRS 2011 ( EPTCS 82 )
IWS 2010 ( EPTCS 44 )
WRS 2009 ( EPTCS 15 )
WRS 2008 ( ENTCS 237(3) )
WRS 2007 ( ENTCS 204 )
WRS 2006 ( ENTCS 174(10) )
WRS 2005
WRS 2004 ( ENTCS 124(2) )
WRS 2003 ( ENTCS 86(4) )
WRS 2002 ( ENTCS 70(6) )
WRS 2001 ( ENTCS 57 )

WRS Account                             
Invited talks
JSC special issue
Round table 2004
Panel discussion 2001

Lists of participants
Open problems
International Workshop on
Reduction Strategies in Rewriting and Programming

Reduction strategies in rewriting and programming have attracted an increasing attention within the last years. New types of reduction strategies have been invented and investigated, and new results on rewriting / computation under particular strategies have been obtained. Research in this field ranges from primarily theoretical questions about reduction strategies to very practical application and implementation issues. The need for a deeper understanding of reduction strategies in rewriting and programming, both in theory and practice, is obvious, since they bridge the gap between unrestricted general rewriting (computation) and (more deterministic) rewriting with particular strategies (programming). Moreover, reduction strategies provide a natural way to go from operational principles (e.g., graph and term rewriting, narrowing, lambda-calculus) and semantics (e.g., normalization, computation of values, infinitary normalization, head-normalization) to implementations of programming languages.

Therefore any progress in this area is likely to be of interest not only to the rewriting community, but also to neighbouring fields like functional programming, functional-logic programming, and termination proofs of algorithms.

The WRS series of workshops wants to provide a forum for the presentation and discussion of new ideas and results, recent developments, new research directions, as well as of surveys on existing knowledge in this area. Furthermore we aim at fostering interaction and exchange between researchers and students actively working on such topics.


Topics of interest include, but are not restricted to:
  • theoretical foundations for the definition and semantic description of reduction strategies
  • strategies in different frameworks (term rewriting, graph rewriting, infinitary rewriting, lambda calculi, higher order rewriting and explicit substitutions, conditional rewriting, rewriting with built-ins, narrowing, constraint solving, etc.) and their application in (equational, functional, functional-logic) programming (languages)
  • properties of reduction strategies / computations under strategies (e.g., completeness, computability, decidability, complexity, optimality, (hyper-)normalization, cofinality, fairness, perpetuality, context-freeness, neededness, laziness, eagerness, strictness)
  • interrelations, combinations and applications of reduction under different strategies (e.g., equivalence conditions for fundamental properties like termination and confluence, applications in modularity analysis, connections between strategies of different frameworks, etc.)
  • program analysis and other semantics-based optimization techniques dealing with reduction strategies
  • rewrite systems / tools / implementations with flexible / programmable strategies as essential concept / ingredient
  • specification of reduction strategies in (real) languages
  • data structures and implementation techniques for reduction strategies


The publication scheme of WRS is traditionally twofold. Accepted papers are included in the preliminary workshop proceedings and available at the workshop. From 2001 to 2008, the final proceedings were published in the Electronic Notes in Theoretical Computer Science (ENTCS) series of Elsevier. Since 2009, the final proceedings are published in the Electronic Proceedings in Theoretical Computer Science (EPTCS) series.

Last update: June 2011 slucas@dsic.upv.es