Safety- and liveness-properties in propositional temporal logic: characterizations and decidability
Semigroups defined by automaton extension mapping
We study semigroups generated by the restrictions of automaton extension (see, e.g., [3]) and give a characterization of automaton extensions that generate finite semigroups.
Semisimplicity of the algebra associated to a biprefix code.
Solid codes and disjunctive domains.
Some Algebraic Properties of Machine Poset of Infinite Words
The complexity of infinite words is considered from the point of view of a transformation with a Mealy machine that is the simplest model of a finite automaton transducer. We are mostly interested in algebraic properties of the underlying partially ordered set. Results considered with the existence of supremum, infimum, antichains, chains and density aspects are investigated.
Some algorithms on the star operation applied to finite languages.
Some Free Submonoids of the Free Monoid of Prefix Codes.
Some results on C-varieties
In an earlier paper, the second author generalized Eilenberg's variety theory by establishing a basic correspondence between certain classes of monoid morphisms and families of regular languages. We extend this theory in several directions. First, we prove a version of Reiterman's theorem concerning the definition of varieties by identities, and illustrate this result by describing the identities associated with languages of the form (a1a2...ak)+, where a1,...,ak are distinct letters. Next,...
Some results on finite maximal codes
Some results on the dot-depth hierarchy.
Some results on -varieties
In an earlier paper, the second author generalized Eilenberg’s variety theory by establishing a basic correspondence between certain classes of monoid morphisms and families of regular languages. We extend this theory in several directions. First, we prove a version of Reiterman’s theorem concerning the definition of varieties by identities, and illustrate this result by describing the identities associated with languages of the form , where are distinct letters. Next, we generalize the notions...
Sous-monoïdes et automates
Sous-monoides et codes avec des mots infinis.
Spezielle Gleichungen in freien Halbgruppen und eine Anwendung auf Normalformen regulärer Ereignisse
Strongly automatic semigroups
Dans cet article, nous introduisons la notion de semi-groupe fortement automatique, qui entraîne la notion d’automaticité des semi-groupes usuelle. On s’intéresse particulièrement aux semi-groupes de développements en base , pour lesquels on obtient un critère de forte automaticité.
Strongly compatible total orders on free monoids.
Sur des points fixes de morphismes d'un monoïde libre
Sur la classification syntaxique.
Sur le calcul du monoïde syntaxique d'un sous monoïde finiment engendré.
Sur le produit de concaténation non ambigu.