Perfect extensions of de Morgan algebras

An algebra $$\mathbf{A}$$ is called a perfect extension of its subalgebra $$\mathbf{B}$$ if every congruence has unique to . This terminology was used by Blyth and Varlet [1994]. In the case lattices, this concept described Grätzer Wehrung [1999] saying that congruence-preserving Not many investigations have been carried out so far. The present authors in another recent study faced question when de Morgan $$\mathbf{M}$$ Boolean $$B(\mathbf{M})$$ , so-called skeleton note full solution interesting problem given. theory natural dualities sense Davey Werner [1983] Clark [1998], as well product representations, are main tools obtain solution.