Abstract

Very recently Albuquerque, Font and Jansana, based on preceding work of Czelakowski on compatibility operators, introduced coherent compatibility operators and used Galois connections, formed by these operators, to provide a unified framework for the study of the Leibniz, the Suszko and the Tarski operators of abstract algebraic logic. Based on this work, we present a unified treatment of the operator approach to the categorical abstract algebraic logic hierarchy of π-institutions. This approach encompasses previous work by the author in this area, started under Don Pigozzi’s guidance, and provides resources for new results on the semantic, i.e., operator-based, side of the hierarchy.