Results 11 to 20 of about 309 (55)

Some operators that preserve the locality of a pseudovariety of semigroups

, 2013
It is shown that if V is a local monoidal pseudovariety of semigroups, then K(m)V, D(m)V and LI(m)V are local. Other operators of the form Z(m)(_) are considered.
ALFREDO COSTA, Almeida J., ANA ESCADA, Eilenberg S., Kad'ourek J., Knast R.   +5 more
core   +1 more source

A Fibrational Approach to Automata Theory [PDF]

, 2015
For predual categories C and D we establish isomorphisms between opfibrations representing local varieties of languages in C, local pseudovarieties of D-monoids, and finitely generated profinite D-monoids.
Chen, Liang-Ting, Urbat, Henning
core   +2 more sources

On FO2 quantifier alternation over words

, 2009
We show that each level of the quantifier alternation hierarchy within FO^2[
H. Straubing, J. Almeida, J.-É. Pin, J.-É. Pin, J.-É. Pin, M. Adler, N. Immerman, P. Tesson, P. Tesson, P. Trotter, P. Weis, T. Schwentick, V. Diekert, W. Thomas   +13 more
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Some pseudovariety joins involving locally trivial semigroups [PDF]

, 2002
This paper is concerned with the computation of pseudovariety joins involving the pseudovariety LI of locally trivial semigroups. We compute, in particular, the join of LI with any subpseudovariety of CRmN, the Mal'cev product of the pseudovariety of ...
Costa, José Carlos
core   +1 more source

Free profinite R-trivial, locally idempotent and locally commutative semigroups [PDF]

, 1999
This paper is concerned with the structure of implicit operations on R intersection with LJ1, the pseudovariety of all R-trivial, locally idempotent and locally commutative semigroups.
A. Azevedo, A. Azevedo, C. Selmi, J. Almeida, J. Almeida, J. Almeida, J. Almeida, J. Almeida, J. Brzozowski, J. Reiterman, J.-E. Pin, J.-E. Pin, José Carlos Costa, L. Simon, M. Zeitoun, P. Weil, R. McNaughton, S. Eilenberg, Y. Zalcstein   +18 more
core   +1 more source

On Varieties of Automata Enriched with an Algebraic Structure (Extended Abstract)

, 2014
Eilenberg correspondence, based on the concept of syntactic monoids, relates varieties of regular languages with pseudovarieties of finite monoids.
Klíma, Ondřej
core   +2 more sources

Formations of monoids, congruences, and formal languages [PDF]

, 2015
The main goal in this paper is to use a dual equivalence in automata theory started in [25] and developed in [3] to prove a general version of the Eilenberg-type theorem presented in [4].
Ballester-Bolinches, Adolfo, Cosme i Llópez, Enric, Esteban Romero, Ramón, Rutten, J.J.M.M.   +3 more
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On the insertion of n-powers

, 2019
In algebraic terms, the insertion of $n$-powers in words may be modelled at the language level by considering the pseudovariety of ordered monoids defined by the inequality $1\le x^n$.
Almeida, J., Klíma, O.
core   +1 more source

Pointlike reducibility of pseudovarieties of the form V*D [PDF]

, 2016
In this paper, we investigate the reducibility property of semidirect products of the form V *D relatively to (pointlike) systems of equations of the form x1 =...= xn, where D denotes the pseudovariety of definite semigroups.
Almeida J., Conceição Nogueira, Eilenberg S., José Carlos Costa, Maria Lurdes Teixeira   +4 more
core   +2 more sources

Varieties of Languages in a Category

, 2015
Eilenberg's variety theorem, a centerpiece of algebraic automata theory, establishes a bijective correspondence between varieties of languages and pseudovarieties of monoids.
Adamek, Jiri, Milius, Stefan, Myers, Robert, Urbat, Henning   +3 more
core   +1 more source