THE POSET OF ALL LOGICS II: LEIBNIZ CLASSES AND HIERARCHY

A Leibniz class is a of logics closed under the formation term-equivalent logics, compatible expansions, and non-indexed products sets logics. We study complete lattice all classes, called hierarchy. In particular, it proved that classes truth-equational assertional are meet-prime in hierarchy, while protoalgebraic equivalential meet-reducible. However, last two shown to be determined by conditions consisting only.