Regularity and irregularity of sequences generated by automata
Let Lϕ,λ = {ω ∈ Σ∗ | ϕ(ω) > λ} be the language recognized by a formal series ϕ:Σ∗ → ℝ with isolated cut point λ. We provide new conditions that guarantee the regularity of the language Lϕ,λ in the case that ϕ is rational or ϕ is a Hadamard quotient of rational series. Moreover the decidability property of such conditions is investigated.
Let Lϕ,λ = {ω ∈ Σ∗ | ϕ(ω) > λ} be the language recognized by a formal series ϕ:Σ∗ → ℝ with isolated cut point λ. We provide new conditions that guarantee the regularity of the language Lϕ,λ in the case that ϕ is rational or ϕ is a Hadamard quotient of rational series. Moreover the decidability property of such conditions is investigated.
Let Lϕ,λ = {ω ∈ Σ∗ | ϕ(ω) > λ} be the language recognized by a formal series ϕ:Σ∗ → ℝ with isolated cut point λ. We provide new conditions that guarantee the regularity of the language Lϕ,λ in the case that ϕ is rational or ϕ is a Hadamard quotient of rational series. Moreover the decidability property of such conditions is investigated.
We show that some natural refinements of the Straubing and Brzozowski hierarchies correspond (via the so called leaf-languages) step by step to similar refinements of the polynomial-time hierarchy. This extends a result of Burtschik and Vollmer on relationship between the Straubing and the polynomial hierarchies. In particular, this applies to the Boolean hierarchy and the plus-hierarchy.
We show that some natural refinements of the Straubing and Brzozowski hierarchies correspond (via the so called leaf-languages) step by step to similar refinements of the polynomial-time hierarchy. This extends a result of Burtschik and Vollmer on relationship between the Straubing and the polynomial hierarchies. In particular, this applies to the Boolean hierarchy and the plus-hierarchy.
The notion of a rough set, developed by Pawlak [10], is an important tool to describe situation of incomplete or partially unknown information. In this article, which is essentially the continuation of [6], we try to give the characterization of approximation operators in terms of ordinary properties of underlying relations (some of them, as serial and mediate relations, were not available in the Mizar Mathematical Library). Here we drop the classical equivalence- and tolerance-based models of rough...
In this study, we are concerned with a two-objective development of information granules completed on a basis of numeric data. The first goal of this design concerns revealing and representing a structure in a data set. As such it is very much oriented towards coping with the underlying it relational aspects of the experimental data. The second goal deals with a formation of a mapping between information granules constructed in two spaces (thus it concentrates on the it directional aspect of information...