ON THE INJECTIVITY OF THE LEIBNIZ OPERATOR
Manuel A. Martins · 2005
The class of weakly algebrizable logics is deflned as the class of logics having monotonic and injective Leibniz operator. We show that \monotonicity cannot be discarded on this deflnition, by presenting an example of a system with injective and non monotonic Leibniz operator. We also show that the non injectivity of the non protoalgebraic inf-sup fragment of the Classic Propositional Calculus, CPC^_, holds only from the fact that the empty set is a CPC^_-fllter.