Free distributive P-algebras: a new approach
Tibor Katriňák · Glasgow Mathematical Journal · 1998
It is well known (Lee [13]) that the class of all distributive p-algebras B = Bω is a variety and that the class of all subvarieties of B forms a chain where B-i is the trivial class, B0 is the class of Boolean algebras, and B1 is the class of Stone algebras.