Universal algebra [5, 9, 4] is the theory of equalities t = u. It is a simple framework within which we can study mathematical structures, for example groups, rings, and fields. It has also been applied to study the mathematical properties of mathematical truth and computability. For example boolean algebras correspond to classical truth, heyting algebras correspond to intuitionistic truth, cyl...

In this paper we introduce MINIMAXSAT, a new Max-SAT solver that incorporates the best SAT and Max-SAT techniques. It can handle hard clauses (clauses of mandatory satisfaction as in SAT), soft clauses (clauses whose falsification is penalized by a cost as in Max-SAT) as well as pseudo-boolean objective functions and constraints. Its main features are: learning and backjumping on hard clauses; ...

LogicWeb has traditionally lacked devices for expressing mutually exclusive clauses. We address this limitation by adopting choice-conjunctive clauses of the form D0&D1 where D0,D1 are Horn clauses and & is a linear logic connective. Solving a goal G using D0&D1 – pv(D0&D1, G) – has the following operational semantics: choose a successful one between pv(D0, G) and pv(D1, G). In other words, if ...