AND JIEH HSIANG

We present a distributed/parallel prover for propositional satisability (SAT), called PSATO, for networks of workstations. PSATO is based on the sequential SAT prover SATO, which is an ecient implementation of the Davis-Putnam algorithm. The master-slave model is used for communication. A simple and eective workload balancing method distributes the workload among workstations. A key property of our method is that the concurrent processes explore disjoint portions of the search space. In this way, we use parallelism without introducing redundant search. Our approach provides solutions to the problems of (i) cumulating intermediate results of separate runs of rea-soning programs; (ii) designing highly scalable parallel algorithms and (iii) supporting \fault-tolerant " distributed computing. Several dozens of open problems in the study of quasigroups have been solved using PSATO. We also show how a useful technique called the cyclic group construction has been coded in propositional logic