Displaying similar documents to “A conjecture on the concatenation product”

Some results on 𝒞 -varieties

Jean-Éric Pin, Howard Straubing (2005)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

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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 ( a 1 a 2 a k ) + , where a 1 , ... , a k are distinct letters. Next, we generalize...

Imre Simon : an exceptional graduate student

Denis Thérien (2005)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

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This short note reviews the main contributions of the Ph.D. thesis of Imre Simon. His graduate work had major impact on algebraic theory of automata and thirty years later we are in a good position to appreciate how sensitive he was in selecting good problems, and how clever in solving them!

Regular languages definable by Lindström quantifiers

Zoltán Ésik, Kim G. Larsen (2003)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

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In our main result, we establish a formal connection between Lindström quantifiers with respect to regular languages and the double semidirect product of finite monoids with a distinguished set of generators. We use this correspondence to characterize the expressive power of Lindström quantifiers associated with a class of regular languages.