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CIE
2007
Springer
13 years 8 months ago
Definability in the Homomorphic Quasiorder of Finite Labeled Forests
Abstract. We prove that for any k 3 each element of the homomorphic quasiorder of finite k-labeled forests is definable, provided that the minimal non-smallest elements are allowe...
Oleg V. Kudinov, Victor L. Selivanov
CIE
2007
Springer
13 years 8 months ago
A Weakly 2-Random Set That Is Not Generalized Low
A guiding question in the study of weak 2-randomness is whether weak 2-randomness is closer to 1-randomness, or closer to 2randomness. Recent research indicates that the first alte...
Andrew Lewis, Antonio Montalbán, Andr&eacut...
CIE
2007
Springer
13 years 8 months ago
Sofic Trace Subshift of a Cellular Automaton
The trace subshift of a cellular automaton is the subshift of all possible columns that may appear in a space-time diagram. In this paper we study conditions for a sofic subshift t...
Julien Cervelle, Enrico Formenti, Pierre Guillon
CIE
2007
Springer
13 years 11 months ago
Computational Complexity of Constraint Satisfaction
Abstract. The input to a constraint satisfaction problem (CSP) consists of a set of variables, each with a domain, and constraints between these variables formulated by relations o...
Heribert Vollmer
CIE
2007
Springer
13 years 11 months ago
Computability and Incomputability
The conventional wisdom presented in most computability books and historical papers is that there were several researchers in the early 1930’s working on various precise defini...
Robert I. Soare
CIE
2007
Springer
13 years 11 months ago
A Useful Undecidable Theory
Abstract. We show that many so called discrete weak semilattices considered earlier in a series of author’s publications have hereditary undecidable first-order theories. Since ...
Victor L. Selivanov
CIE
2007
Springer
13 years 11 months ago
Refocusing Generalised Normalisation
Abstract. When defined with general elimination/application rules, natural deduction and λ-calculus become closer to sequent calculus. In order to get real isomorphism, normalisa...
José Espírito Santo
CIE
2007
Springer
13 years 11 months ago
From Logic to Physics: How the Meaning of Computation Changed over Time
The intuition guiding the de…nition of computation has shifted over time, a process that is re‡ected in the changing formulations of the Church-Turing thesis. The theory of co...
Itamar Pitowsky
CIE
2007
Springer
13 years 11 months ago
Nash Stability in Additively Separable Hedonic Games Is NP-Hard
Ballester has shown that the problem of deciding whether a Nash stable partition exists in a hedonic game with arbitrary preferences is NP-complete. In this paper we will prove tha...
Martin Olsen
CIE
2007
Springer
13 years 11 months ago
Locally Computable Structures
We introduce the notion of a locally computable structure, a natural way of generalizing the notions of computable model theory to uncountable structures S by presenting the finit...
Russell G. Miller