Negative Equivalence of Extensions of Minimal Logic

摘要

Two logics L 1 and L 2 are negatively equivalent if for any set of formulas X and any negated formula ¬ϕ, ¬ϕ can be deduced from the set of hypotheses X in L 1 if and only if it can be done in L 2. This article is devoted to the investigation of negative equivalence relation in the class of extensions of minimal logic.