Vol. 67,   2   (1998) pp.   249-271
OPTIMAL NATURAL DUALITIES FOR SOME QUASIVARIETIES OF DISTRIBUTIVE DOUBLE $p$-ALGEBRAS
M. J. SARAMAGO
Abstract. 
Quasivarieties of distributive double $p$-algebras generated by an ordinal sum $nderline M$ of two Boolean lattices are considered. Globally minimal failsets within $\Bbb S(nderline M^2)$ are completely determined; from them all the optimal dualities for these quasivarieties are obtained.