EuDML | Browse

We give several characterisations of strongly projective graphs which generalise in many respects odd cycles and complete graphs [7]. We prove that all known families of projective graphs contain only strongly projective graphs, including complete graphs, odd cycles, Kneser graphs and non-bipartite distance-transitive graphs of diameter d ≥ 3.

Fast algorithms for finding a subdirect decomposition and interesting congruences of finite algebras

Jiří Demel (1982)

Kybernetika

Finite hull systems and their implication bases. (Endliche Hüllensysteme und ihre Implikationenbasen.)

König, Roman (2002)

Séminaire Lotharingien de Combinatoire [electronic only]

Finitely generated relations and their applications to permutable and $n$ -permutable varieties

Ivan Chajda, Jaromír Duda (1982)

Commentationes Mathematicae Universitatis Carolinae

Formal Translation Monoid and Algebra Congruences in a Monodial Category.

Symeon Bozapalides, Anestis Firarides (1982)

Monatshefte für Mathematik

Four-part semigroups - semigroups of Boolean operations

Prakit Jampachon, Yeni Susanti, Klaus Denecke (2012)

Discussiones Mathematicae - General Algebra and Applications

Four-part semigroups form a new class of semigroups which became important when sets of Boolean operations which are closed under the binary superposition operation f + g := f(g,...,g), were studied. In this paper we describe the lattice of all subsemigroups of an arbitrary four-part semigroup, determine regular and idempotent elements, regular and idempotent subsemigroups, homomorphic images, Green's relations, and prove a representation theorem for four-part semigroups.

Free groupoids with axioms of the form $x^{m + 1} y = x y$ and/or $x y^{n + 1} = x y$ .

Čupona, Ǵorǵi, Celakoski, Naum, Janeva, Biljana (1999)

Novi Sad Journal of Mathematics

Free trees and the optimal bound in Wehrung's theorem

Pavel Růžička (2008)

Fundamenta Mathematicae

We prove that there is a distributive (∨,0,1)-semilattice of size ℵ₂ such that there is no weakly distributive (∨,0)-homomorphism from $C o n_{c} A$ to with 1 in its range, for any algebra A with either a congruence-compatible structure of a (∨,1)-semi-lattice or a congruence-compatible structure of a lattice. In particular, is not isomorphic to the (∨,0)-semilattice of compact congruences of any lattice. This improves Wehrung’s solution of Dilworth’s Congruence Lattice Problem, by giving the best cardinality...

Function minimum associated to a congruence on integral n-tuple space.

J.C. Rosales (1995)

Semigroup forum

Fuzzy congruences on groups and rings.

Samhan, Marouf A., Ahsanullah, T.M.G. (1994)

International Journal of Mathematics and Mathematical Sciences

Currently displaying 1 – 13 of 13

Page 1