DE MORGAN ALGEBRAS WITH DOUBLE DEMI-PSEUDOCOMPLEMENTATION

摘要

The variety ddpM of de Morgan algebras with double demi-pseudocomplementation consists of those algebras (L; ∧,∨,°,*,+,0,1) of type (2,2,1,1,1,0,0) where (L;∧,∨,°,0,1) is a de Morgan algebra,(L;∧,∨,*,+,0,1) is a double demi-p-lattice and the operations x → x°,x x* and x → x+ are linked by the identities x*° =x°*,x+° =x°+and x*+ =x+*.In this paper,we characterize congruences on a ddpM-algebra,and give a description of the subdirectly irreducible algebras.