Published: 26th January 2010
DOI: 10.4204/EPTCS.15
ISSN: 2075-2180

EPTCS 15

Proceedings Ninth International Workshop on
Reduction Strategies in Rewriting and Programming
Brasilia, Brazil, 28th June 2009

Edited by: Maribel Fernández
Preface
Maribel Fernandez
Extensional and Intensional Strategies
Tony Bourdier, Horatiu Cirstea, Daniel Dougherty and Hélène Kirchner		1
Superdevelopments for Weak Reduction
Eduardo Bonelli and Pablo Barenbaum		20
Strategies in PRholog
Besik Dundua, Temur Kutsia and Mircea Marin		32
Specification of Products and Product Lines
Ariel Gonzalez and Carlos Luna		44
Extending Context-Sensitivity in Term Rewriting
Bernhard Gramlich and Felix Schernhammer		56
Principal Typings in a Restricted Intersection Type System for Beta Normal Forms with De Bruijn Indices
Daniel Ventura, Mauricio Ayala-Rincón and Fairouz Kamareddine		69
Stream Productivity by Outermost Termination
Hans Zantema and Matthias Raffelsieper		83

Preface

EPTCS: 9th International Workshop on Reduction Strategies in Rewriting and programming - WRS 2009

The WRS workshops promote research and collaboration in the area of reduction strategies and their applications in specification, programming, software engineering and theorem proving, amongst others. Reduction strategies define which (sub)expression(s) should be selected for evaluation and which rule(s) should be applied. These choices affect fundamental properties of reductions, such as completeness, laziness and efficiency in general. Programming languages such as Elan, Maude, OBJ, Stratego, and TOM allow the explicit definition of the evaluation strategy, whereas languages such as Clean, Curry, and Haskell allow its modification.

This volume contains selected papers presented at the 9th International Workshop on Reduction Strategies in Rewriting and Programming, WRS 2009. In addition to an invited contribution by Tony Bourdier, Horatiu Cirstea, Daniel Dougherty and Hélène Kirchner, which discusses the foundations for the definition and analysis of reduction strategies, this volume includes six papers covering a wide range of topics, including the use of strategies in lambda-calculus and rewriting to obtain weak or strong normalisation of the computation process, strategies in logic programming languages, and the use of rule systems with appropriate strategies to solve software engineering problems.

The workshop WRS 2009 was held in Brasilia on the 28th June 2009, associated to RTA 2009 (the 20th International Conference on Rewriting Techniques and Applications), and was part of the Federated Conference on Rewriting, Deduction and Programming (RDP). Previous editions of the workshop were held in Utrecht (2001), Copenhagen (2002), Valencia (2003), Aachen (2004), Nara (2005), Seattle (2006), Paris (2007) and Hagenberg (2008).

The Programme Committee of WRS 2009 consisted of:

I would like to thank all those who contributed to WRS 2009, and in particular the Programme Committee members, the reviewers, and the local organisers of the Federated Conference on Rewriting, Deduction and Programming for their support and efficient work.

Maribel Fernández
London, December 2009