Freese, Ralph2013-02-092013-02-092013-02-08http://hdl.handle.net/10125/25949T. Dent, K. Kearnes and A. Szendrei de ne the derivative, 0, of a set of equations and show, for idempotent , that implies congruence modularity if 0 is inconsistent ( 0 j= x y). In this paper we investigate other types of derivatives that give similar results for congruence n-permutable for some n, and for congruence semidistributivity.11en-USAttribution-NonCommercial-NoDerivs 3.0 United Statesn-permutability, semidistributivity, congruence latticeArticle