Moraschini, TommasoRaftery, James G.2019-10-012019-09Moraschini, T. & Raftery, J.G. On prevarieties of logic. Algebra universalis (2019) 80: 37. https://doi.org/10.1007/s00012-019-0611-7.0002-5240 (print)1420-8911 (online)10.1007/s00012-019-0611-7http://hdl.handle.net/2263/71517It is proved that every prevariety of algebras is categorically equivalent to a ‘prevariety of logic’, i.e., to the equivalent algebraic semantics of some sentential deductive system. This allows us to show that no nontrivial equation in the language ∧,∨,∘ holds in the congruence lattices of all members of every variety of logic, and that being a (pre)variety of logic is not a categorical property.en© Springer Nature Switzerland AG 2019. The original publication is available at : https://link.springer.com/journal/12.Prevariety of logicAlgebraizable logicMaltsev classPostprint Article