Représentation des algèbres universelles par des faisceaux
Representation of connected monounary algebras by means of irreducibles
The aim of the present paper is to describe all connected monounary algebras for which there exists a representation by means of connected monounary algebras which are retract irreducible in the class (or in ).
Representation of involuted semigroups by binary relations
Representation of ordered classes by classes of connected unary algebras
Representation of undirected graphs by anticommutative conservative groupoids
The paper studies tolerances and congruences on anticommutative conservative groupoids. These groupoids can be assigned in a one-to-one way to undirected graphs.
Residual finiteness of a class of semigroups presented by a single relation.
Residually finite congruences and quasi-regular subsets in uniform algebras
Restricted congruence regularity of algebras.
Retract irreducibility of connected monounary algebras. I
Retract irreducibility of connected monounary algebras. II
Retract irreducibility of monounary algebras
Retract varieties of monounary algebras
Retracts and monomorphism monoids in semigroup varieties.
Retracts and Q-independence
A non-empty set X of a carrier A of an algebra A is called Q-independent if the equality of two term functions f and g of the algebra A on any finite system of elements a₁,a₂,...,aₙ of X implies f(p(a₁),p(a₂),...,p(aₙ)) = g(p(a₁),p(a₂),...,p(aₙ)) for any mapping p ∈ Q. An algebra B is a retract of A if B is the image of a retraction (i.e. of an idempotent endomorphism of B). We investigate Q-independent subsets of algebras which have a retraction in their set of term functions.
Retracts of monounary algebras corresponding to groupoids
Rigid Boolean Algebras
Ring-like structures corresponding to generalized orthomodular lattices
Root decomposition of the ternary Mal'tsev algebra .
Rough subalgebras of some binary algebras connected with logics.
Schreier-Zassenhaus theorem for algebras. I