Displaying similar documents to “Central extensions in Mal'tsev varieties.”

Congruence restrictions on axes

Jaromír Duda (1992)

Mathematica Bohemica

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We give Mal’cev conditions for varieties 4V4 whose congruences on the product A × B , A , B V , are determined by their restrictions on the axes in A × B .

Some modifications of congruence permutability and dually congruence regular varietie

Ivan Chajda, Günther Eigenthaler (2001)

Discussiones Mathematicae - General Algebra and Applications

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It is well known that every congruence regular variety is n-permutable (in the sense of [9]) for some n ≥ 2. For the explicit proof see e.g. [2]. The connections between this n and Mal'cev type characterizations of congruence regularity were studied by G.D. Barbour and J.G. Raftery [1]. The concept of local congruence regularity was introduced in [3]. A common generalization of congruence regularity and local congruence regularity was given in [6] under the name "dual congruence regularity...