 The logic \(\bL^{\{\wedge , \vee \}}\) is thus a natural example of a logic where the class of algebras of its reduced matrix models is not the right class of algebras expected to correspond to it (see Font &amp; Verdú 1991 where the logic is studied at length). The properties of this example and its treatment in Font &amp; Verdú 1991 motivated the systematic study in Font &amp; Jansana 1996 of the kind of models for sentential logics considered in Brown &amp; Suszko 1973, namely, abstract logics.