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Plenary stable quasigroups

Philip Holgate (1991)

Commentationes Mathematicae Universitatis Carolinae

Some results are obtained for quasigroups in which the operation of iterated squaring always leads to stability irrespective of the initial element.

Polyabelian loops and Boolean completeness

François Lemieux, Cristopher Moore, Denis Thérien (2000)

Commentationes Mathematicae Universitatis Carolinae

We consider the question of which loops are capable of expressing arbitrary Boolean functions through expressions of constants and variables. We call this property Boolean completeness. It is a generalization of functional completeness, and is intimately connected to the computational complexity of various questions about expressions, circuits, and equations defined over the loop. We say that a loop is polyabelian if it is an iterated affine quasidirect product of Abelian groups; polyabelianness...

Possible orders of nonassociative Moufang loops

Orin Chein, Andrew Rajah (2000)

Commentationes Mathematicae Universitatis Carolinae

The paper surveys the known results concerning the question: “For what values of n does there exist a nonassociative Moufang loop of order n ?” Proofs of the newest results for n odd, and a complete resolution of the case n even are also presented.

Powers and alternative laws

Nicholas Ormes, Petr Vojtěchovský (2007)

Commentationes Mathematicae Universitatis Carolinae

A groupoid is alternative if it satisfies the alternative laws x ( x y ) = ( x x ) y and x ( y y ) = ( x y ) y . These laws induce four partial maps on + × + ( r , s ) ...

Powers of elements in Jordan loops

Kyle Pula (2008)

Commentationes Mathematicae Universitatis Carolinae

A Jordan loop is a commutative loop satisfying the Jordan identity ( x 2 y ) x = x 2 ( y x ) . We establish several identities involving powers in Jordan loops and show that there is no nonassociative Jordan loop of order 9 .

Presolid varieties of n-semigroups

Avapa Chantasartrassmee, Jörg Koppitz (2005)

Discussiones Mathematicae - General Algebra and Applications

he class of all M-solid varieties of a given type t forms a complete sublattice of the lattice ℒ(τ) of all varieties of algebrasof type t. This gives a tool for a better description of the lattice ℒ(τ) by characterization of complete sublattices. In particular, this was done for varieties of semigroups by L. Polák ([10]) as well as by Denecke and Koppitz ([4], [5]). Denecke and Hounnon characterized M-solid varieties of semirings ([3]) and M-solid varieties of groups were characterized by Koppitz...

Products of partially ordered quasigroups

Milan Demko (2008)

Commentationes Mathematicae Universitatis Carolinae

We describe necessary and sufficient conditions for a direct product and a lexicographic product of partially ordered quasigroups to be a positive quasigroup. Analogous questions for Riesz quasigroups are studied.

Projection representable relations on Menger ( 2 , n ) -semigroups

Wiesław Aleksander Dudek, Valentin S. Trokhimenko (2008)

Czechoslovak Mathematical Journal

Abstract characterizations of relations of nonempty intersection, inclusion end equality of domains for partial n -place functions are presented. Representations of Menger ( 2 , n ) -semigroups by partial n -place functions closed with respect to these relations are investigated.

Pseudoautomorphisms of Bruck loops and their generalizations

Mark Greer, Michael Kinyon (2012)

Commentationes Mathematicae Universitatis Carolinae

We show that in a weak commutative inverse property loop, such as a Bruck loop, if α is a right [left] pseudoautomorphism with companion c , then c [ c 2 ] must lie in the left nucleus. In particular, for any such loop with trivial left nucleus, every right pseudoautomorphism is an automorphism and if the squaring map is a permutation, then every left pseudoautomorphism is an automorphism as well. We also show that every pseudoautomorphism of a commutative inverse property loop is an automorphism, generalizing...

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