Preface This volume contains the proceedings of PDPAR’03, the first workshop on Pragmatics of Decision Procedures in Automated Reasoning, held July 29, 2003, in Miami, Florida (USA). The main goal of PDPAR’03 was to bring together researchers interested in the pragmatic aspects of decision procedures in automated reasoning, giving them a fo- rum for presenting and discussing implementation and evaluation techniques. Another goal of the workshop was to provide the occasion to discuss the future of SMT-LIB, a research initiative aimed at establishing a common standard for the specification of benchmarks and background theories for satisfiability modulo theories, and at creating a repository of such benchmarks. (See http://combination.cs.uiowa.edu/ smtlib/ for more information.) To this end, the workshop hosted a panel discussion on the SMT-LIB format. These proceedings contain seven regular submission papers, each of which was re- viewed by at least two members of the Program Committee. The papers present and discuss: decision procedures for various extensions of a decidable fragment of set the- ory; a programming language for implementing (combination of) decision procedures; proof production for a combination of SAT solving and first-order decision procedures; abstraction techniques for efficiently handling fragments of the theory of reals; a combi- nation of BDDs and first-order decision procedures; an application of a combination of SAT solving and decision procedures for fragments of arithmetics to the verification of hybrid systems; and a description of a collection of benchmarks for first-order decision procedures extracted from the verification of microprocessors. We welcomed one invited lecture by Mark Stickel on “Specialized Reasoning in SNARK”. A short abstract of Stickel’s talk is included in this volume. Finally, also included in this volume is a white paper by these organisers on a common format for SMT-LIB. The paper was used as the starting point of a panel discussion among the fol- lowing panelists: Aaron Stump, Clark Barrett, Greg Nelson, Roberto Sebastiani, Geoff Sutcliffe, and ourselves. We would like to thank the members of the program committee and the two external referees for their care and time in reviewing the submitted papers. We also thank the members of the organising committee of CADE-19 (to which this workshop is affili- ated) for their help in the practical organisation of the workshop; and the institutions that supported the workshop: CADE Inc. and INRIA. Silvio Ranise and Cesare Tinelli PDPAR co-chairs Nancy and Iowa City, August 2003