Tractable Classes in Exactly-One-SAT

Abstract

In this paper, we aim at proposing a new approach for defining tractable classes for Exactly-One-SAT problem (in short EO-SAT). EO-SAT is the problem of deciding whether a given CNF formula has a model so that each clause has exactly one true literal. Our first tractable class is defined by using a simple property that has to be satisfied by every three clauses sharing at least one literal. In a similar way, our second tractable class is obtained from a property that has to be satisfied by particular sequences of clauses. The proposed tractable classes can, in a sense, be seen as natural counterparts of tractable classes of the maximum independent set problem.