About some UP-based polynomial fragments of SAT.

This paper explores several polynomial fragments of SAT that are based on the unit propagation (UP) mechanism. As a first case study, one Tovey's polynomial fragment of SAT is extended through the use of UP. Then, we answer an open question about connections between the so-called UP-Horn class (and other UP-based polynomial variants) and Dalal's polynomial Quad class. Finally, we introduce an extended UP-based pre-processing procedure that allows us to prove that some series of benchmarks from the SAT competitions are polynomial ones. Moreover, our experimentations show that this pre-processing can speed-up the satisfiability check of other instances. [ABSTRACT FROM AUTHOR]