On irregular varieties which contain cyclic involutions

Leonard Roth

Displaying similar documents to “On irregular varieties which contain cyclic involutions”

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...

On the structure of equationally complete varieties. I

Don Pigozzi (1981)

Colloquium Mathematicae

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Trapezoid lemma and congruence distributivity

Ivan Chajda, Gábor Czédli, Eszter K. Horváth (2003)

Mathematica Slovaca

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The egg-box property of congruences

Ivan Chajda (1988)

Mathematica Slovaca

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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 $A \times B, A, B \in V$ , are determined by their restrictions on the axes in $A \times B$ .

Congruence submodularity

Ivan Chajda, Radomír Halaš (2002)

Discussiones Mathematicae - General Algebra and Applications

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We present a countable infinite chain of conditions which are essentially weaker then congruence modularity (with exception of first two). For varieties of algebras, the third of these conditions, the so called 4-submodularity, is equivalent to congruence modularity. This is not true for single algebras in general. These conditions are characterized by Maltsev type conditions.