This volume contains the papers presented at SAT 2009: 12th International Conference on Theory
and Applications of Satis?ability Testing held from June 30 to July 3 2009 in Swansea (UK).
The International Conference on Theory and Applications of Satis?ability Testing (SAT) started
in 1996 as a series of workshops and in parallel with the growthof SAT developedinto the
main eventfor SAT research. This year'sc- ference testi?ed to the strong interest in SAT
regarding theoretical research - searchonalgorithms investigationsintoapplications
anddevelopmentofsolvers and software systems. As a core problem of computer science SAT is
central for many research areas and has deep interactions with many mathematical s- jects.
Major impulses for the development of SAT came from concrete practical applications as well as
from fundamental theoretical research. This fruitful c- laboration can be seen in virtually all
papers of this volume. There were 86 submissions (completed papers within the scope of the c-
ference). Each submission was reviewed by at least three and on average 4. 0 Programme
Committee members. The Committee decided to accept 45 papers consisting of 34 regular and 11
short papers (restricted to 6 pages). A main n- elty was a shepherding process where 29% of
the papers were accepted only conditionally and requirements on necessary improvements were
formulated by the ProgrammeCommittee and its installment monitored by the shepherd for
thatpaper(using possibly severalroundsoffeedback).
