POS-18: Editor's Preface

The success of solver technologies for declarative languages, such as SAT, in the last decade is mainly due to both the availability of numerous efficient solver implementations and to the growing number of problems that can efficiently be solved through the declarative approach. Designing efficient solvers requires both understanding of the fundamental algorithms underlying the solvers and in-depth insights into how to implement the algorithms for obtaining efficient and robust solvers.

The aim of the Pragmatics of SAT (PoS) workshop series is to provide a venue for researchers working on designing and/or applying Boolean satisfiability (SAT) solvers and related solver technologies to meet, communicate, and discuss latest results. A particular aim of the workshop is to allow researchers to share both fundamental theoretical insights into practical solvers, as well as new implementation-level insights and 'gory' technical details about their systems that may at times be difficult to publish in the main conferences on the declarative solving paradigms.

This volume contains a total of 10 papers presented at two editions of PoS: 

• Four papers from the sixth edition, Pragmatics of SAT 2015, held on September 23, 2015 in Austin, Texas, USA, chaired by Daniel Le Berre, Olivier Roussel, and Allen Van Gelder, with Josep Argelich, Frank Hutter, Laurent Simon, and Takehide Soh as additional program committee members.
• Six papers from the most recent ninth edition, Pragmatics of SAT 2018, held on July 7, 2018 in Oxford, UK, chaired by Daniel Le Berre and Matti Järvisalo, with Mario Alviano, Armin Biere, Bart Bogaerts, Vijay Ganesh, Marijn Heule, Antti Hyvärinen, Alexey Ignatiev, Florian Lonsing, Ruben Martins, Nina Narodytska, and Olivier Roussel as additional program committee members.

The papers cover a range of practical aspects of SAT, including restart schemes, proof logging, parallel SAT solving, runtime prediction, parameter tuning, applications and benchmarking. 

We would like to thank the organizers of the SAT conferences for hosting the workshop yearly with the conference since 2010, in particular, Marijn Heule and Sean Weaver for the 2015 edition and Olaf Beyersdorff and Christoph M. Wintersteiger for the 2018 edition. We also would like to thank Moshe Vardi, Daniel Kroening and Marta Kwiatkowska for the organization of the 2018 Federated Logic Conference (FLoC) that hosted the 2018 edition in Oxford.

We are also grateful to EasyChair for allowing the program committees of Pragmatics of SAT to efficiently manage the submissions and for hosting our proceedings in the EasyChair Proceedings in Computing series.