21 citations · 84 across the 35 of their papers we have counts for
7 papers · 1 filter
Free inductive K-semialgebras
Zoltan Esik, Werner Kuich
We consider rational power series over an alphabet with coefficients in a ordered commutative semiring and characterize them as the free ordered -semialgebras in various…
Representing Small Ordinals by Finite Automata
Zoltan Ésik
It is known that an ordinal is the order type of the lexicographic ordering of a regular language if and only if it is less than omega^omega. We design a polynomial time algorithm…
Free iterative and iteration K-semialgebras
Zoltan Esik, Werner Kuich
We consider algebras of rational power series over an alphabet with coefficients in a commutative semiring and characterize them as the free algebras in various classes of…
Simulations of Weighted Tree Automata
Zoltán Ésik, Andreas Maletti
Simulations of weighted tree automata (wta) are considered. It is shown how such simulations can be decomposed into simpler functional and dual functional simulations also called f…
Simulation vs. Equivalence
Zoltan Esik, Andreas Maletti
For several semirings S, two weighted finite automata with multiplicities in S are equivalent if and only if they can be connected by a chain of simulations. Such a semiring S is c…
An undecidable property of context-free languages
Zoltan Esik
We prove that there exists no algorithm to decide whether the language generated by a context-free grammar is dense with respect to the lexicographic ordering. As a corollary to th…