Results 21 to 30 of about 57 (45)
On fixed points of the lower set operator [PDF]
, 2015 International audienceLower subsets of an ordered semigroup form in a natural way an ordered semigroup. This lower set operator gives an analogue of the power operator already studied in semigroup theory.
Almeida, Jorge +7 more
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Semidirect products of categories and applications [PDF]
, 1999 This paper offers definitions for the semidirect product of categories, Cayley graphs for categories, and the kernel of a relational morphism of categories which will allow us to construct free (profinite) objects for the semidirect product of two ...
Benjamin Steinberg, Steinberg, Benjamin
core +1 more source
Implicit operations on certain classes of semigroups
, 1986 Varieties of algebras are characterized by identities, where an identity is a formal equality of two terms (i.e., operations defined by means of the underlying operations).
Almeida, Jorge, Azevedo, Assis
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A classification of rational languages by semilattice-ordered monoids [PDF]
, 2004 summary:We prove here an Eilenberg type theorem: the so-called conjunctive varieties of rational languages correspond to the pseudovarieties of finite semilattice-ordered monoids. Taking complements of members of a conjunctive variety of languages we get
Polák, Libor
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Complete congruences on lattices of varieties and of pseudovarieties
, 1998 Three methods for the construction of all complete congruences on the lattice Lv(V) of subvarieties of a variety V are introduced. It is shown that there exists an order preserving embedding of the lattice of complete congruences on the lattice Lp(P) of ...
Pastijn, F (15483074) +1 more
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Congruences and Varieties of Finite Semigroups
, 1998 : A classification scheme for regular languages or finite semigroups was proposed by Pin through tree hierarchies, a scheme related to the concatenation product, an operation on languages, and to the Schützenberger product, an operation on semigroups ...
F Blanchet-Sadri
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Uniformities on free semigroups J.-E. Pin and P. Weil
, 2008 Résumé. On sait que les complétions profinies d’un semigroupe libre qui sont associées à une pseudovariété de semigroupes ou de semigroupes ordonnés peuvent être définies par un écart ou un quasi-écart.
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FINITE SEMIGROUPS, FEEDBACK, AND THE LETICHEVSKY CRITERIA ON NON-EMPTY WORDS IN FINITE AUTOMATA
, 2008 . This paper relates classes of finite automata under various feedback products to some well-known pseudovarieties of finite semigroups via a study of their irreducible divisors (in the sense of Krohn-Rhodes).
John +3 more
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The lattice of pseudovarieties of idempotent semigroups and a non-regular analogue
, 1997 We use classical results on the lattice ℒ (ℬ) of varieties of band (idempotent) semigroups to obtain information on the structure of the lattice Ps(DA) of subpseudovarieties of DA, - where DA is the largest pseudovariety of finite semigroups in which
Trotter, PG (15477434) +1 more
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The Lattice of Pseudovarieties of Idempotent Semigroups and a Non-Regular Analogue
: We use classical results on the lattice L(B) of varieties of band (idempotent) semigroups to obtain information on the structure of the lattice P s(DA) of subpseudovarieties of DA, --- where DA is the largest pseudovariety of finite semigroups in ...
P. Trotter, P. Weil
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