Principal congruences of pseudocomplemented semilattices and congruence extension property
Hanamantagouda P. Sankappanavar · Proceedings of the American Mathematical Society · 1979
Principal congruences of pseudocomplemented semilattices are characterized and shown to be definable. This characterization is then applied to give a new proof of the fact that the variety of pseudocomplemented semilattices has the congruence extension property.