Algebraic modal correspondence: Sahlqvist and beyond
Willem Conradie, Ra Palmigiano Sumit Sourabh · 2010
This paper provides a bridge in the gap between the model-theoretic and the algebraic side of modal correspondence theory. We give a new, algebraic proof of the classical Sahlqvist correspondence theorem, as well as a new, algebraic proof of the analogous result for the atomic inductive formulas, which form a proper extension of the Sahlqvist class. 1