82
Voted
ITA
2008
14 years 11 months ago
2008
A set T L is a Parikh test set of L iff c(T ) is a test set of c(L). We give an effective characterization of Parikh test sets for arbitrary commutative language.
61
Voted
ITA
2008
14 years 11 months ago
2008
89
Voted
ITA
2008
14 years 11 months ago
2008
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 ...
73
Voted
ITA
2008
14 years 11 months ago
2008
The necessary and sufficient conditions are extracted for periodicity of bi-ideals. By the way two proper subclasses of uniformly recurrent words are introduced.
92
Voted
ITA
2008
14 years 11 months ago
2008
A language L A is literally idempotent in case that ua2 v L if and only if uav L, for each u, v A , a A. Varieties of literally idempotent languages result naturally by taking...
64
Voted
ITA
2008
14 years 11 months ago
2008
82
Voted
ITA
2008
14 years 11 months ago
2008
We prove that there exists a structure M whose monadic second order theory is decidable, and such that the elementary theory of every expansion of M by a constant is undecidable. 1...
ITA
2008
14 years 11 months ago
2008
110
Voted
ITA
2008
14 years 11 months ago
2008
We prove two cases of a strong version of Dejean's conjecture involving extremal letter frequencies. The results are that there exist an infinite " 5 4 + " -free wor...
75
Voted
ITA
2008
14 years 11 months ago
2008
In this article, we study the complexity of drunken man infinite words. We show that these infinite words, generated by a deterministic and complete countable automaton, or equival...