Characterizations of Several Maltsev Conditions
نویسندگان
چکیده
Tame congruence theory identifies six Maltsev conditions associated with locally finite varieties omitting certain types of local behaviour. Extending a result of Siggers, we show that of these six Maltsev conditions only two of them are equivalent to strong Maltsev conditions for locally finite varieties. Besides omitting the unary type [24], the only other of these conditions that is strong is that of omitting the unary and affine types. We also provide novel presentations of some of the above Maltsev conditions.
منابع مشابه
Deciding some Maltsev conditions in finite idempotent algebras
In this paper we investigate the computational complexity of deciding if a given finite algebraic structure satisfies a certain type of existential condition on its set of term operations. These conditions, known as Maltsev conditions, have played a central role in the classification, study, and applications of general algebraic structures. Several well studied properties of equationally define...
متن کاملMaltsev Families of Varieties Closed under Join or Maltsev Product
Maltsev families of varieties which are closed under join or Maltsev product are investigated. New Maltsev conditions for congruence semi-distributivity are given.
متن کاملOn Maltsev Conditions associated with omitting certain types of local structures
Tame congruence theory identifies six Maltsev conditions associated with locally finite varieties omitting certain subsets of types of local behaviour. Extending a result of Siggers, we show that of these six Maltsev conditions only two of them are equivalent to strong Maltsev conditions for locally finite varieties. Besides omitting the unary type [18], the only other of these conditions that ...
متن کاملOn the Complexity of Some Maltsev Conditions
This paper studies the complexity of determining if a finite algebra generates a variety that satisfies various Maltsev conditions, such as congruence distributivity or modularity. For idempotent algebras we show that there are polynomial time algorithms to test for these conditions but that in general these problems are EXPTIME complete. In addition, we provide sharp bounds in terms of the siz...
متن کاملCharacterizations of Certain Marshall-Olkin Generalized Distributions
Several characterizations of Marshall-Olkin generalized distributions, introduced by Gui (2013) and by Al-Saiari et al. (2014) are presented. These characterizations are based on: (i) a simple relationship between two truncated moments ; (ii) the hazard function.
متن کامل