Comment.Math.Univ.Carolin. 50,3 (2009) 349–357 349 Relatively pseudocomplemented directoids

Abstract. The concept of relative pseudocomplement is introduced in a commuta-tive directoid. It is shown that the operation of relative pseudocomplementation can be characterized by identities and hence the class of these algebras forms a variety. This variety is congruence weakly regular and congruence distributive. A description of congruences via their kernels is presented and the kernels are characterized as the so-called p-ideals