Monotonic valuations and valuations of triads of higher types
Mono-unary algebras in the work of Czechoslovak mathematicians
Monounary algebras with two direct limits
In this paper we describe all algebras with one unary operation such that by a direct limit construction exactly two nonisomorphic algebras can be obtained from .
Morita equivalence of algebraic theories
Morphisms fixing words associated with exchange of three intervals
We consider words coding exchange of three intervals with permutation (3,2,1), here called 3iet words. Recently, a characterization of substitution invariant 3iet words was provided. We study the opposite question: what are the morphisms fixing a 3iet word? We reveal a narrow connection of such morphisms and morphisms fixing Sturmian words using the new notion of amicability.
Morphisms of a certain class of monounary algebras
Morphisms preserving the set of words coding three interval exchange
Any amicable pair ϕ, ψ of Sturmian morphisms enables a construction of a ternary morphism η which preserves the set of infinite words coding 3-interval exchange. We determine the number of amicable pairs with the same incidence matrix in SL±(2,ℕ) and we study incidence matrices associated with the corresponding ternary morphisms η.
Morphisms preserving the set of words coding three interval exchange∗∗∗
Any amicable pair ϕ, ψ of Sturmian morphisms enables a construction of a ternary morphism η which preserves the set of infinite words coding 3-interval exchange. We determine the number of amicable pairs with the same incidence matrix in SL±(2,ℕ) and we study incidence matrices associated with the corresponding ternary morphisms η.
M-Solid Subvarieties of some Varieties of Commutative Semigroups
∗ The research of the author was supported by the Alexander v. Humboldt-Stiftung.The basic concepts are M -hyperidentities, where M is a monoid of hypersubstitutions. The set of all M -solid varieties of semigroups forms a complete sublattice of the lattice of all varieties of semigroups. We fix some specific varieties V of commutative semigroups and study the set of all M -solid subvarieties of V , in particular, if V is nilpotent.
Multiple left distributive systems
We describe the free objects in the variety of algebras involving several mutually distributive binary operations. Also, we show how an associative operation can be constructed on such systems in good cases, thus obtaining a two way correspondence between LD-monoids (sets with a left self-distributive and a compatible associative operation) and multi-LD-systems (sets with a family of mutually distributive operations).
Multiple radical theories
Multiplicity type and subalgebra structure in infinitary universal algebras
Multiplicity types of algebras - an example
m-арные -кольцоиды
-permutable locally finitely presentable categories.
Natural dualities for varieties of distributive lattices with a quantifier
Návod ke studiu algebry pro začátečníky
ndependence of axioms for biordered sets.
Nd-solid varieties
A non-deterministic hypersubstitution maps any operation symbol of a tree language of type τ to a set of trees of the same type, i.e. to a tree language. Non-deterministic hypersubstitutions can be extended to mappings which map tree languages to tree languages preserving the arities. We define the application of a non-deterministic hypersubstitution to an algebra of type τ and obtain a class of derived algebras. Non-deterministic hypersubstitutions can also be applied to equations of type τ. Formally,...
Nearly-idempotent plain algebras are indeed nearly idempotent plain algebras