منابع مشابه
Alternation on Cellular Automata
In this paper we consider several notions of alternation in cellular automata: non-uniform, uniform and weak alternation. We study relations among these notions and with alternating Turing machines. It is proved that the languages accepted in polynomial time by alternating Turing machines are those accepted by alternating cellular automata in polynomial time for all the proposed alternating cel...
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in this thesis, first the notion of weak mutual associativity (w.m.a.) and the necessary and sufficient condition for a $(l,gamma)$-associated hypersemigroup $(h, ast)$ derived from some family of $lesssim$-preordered semigroups to be a hypergroup, are given. second, by proving the fact that the concrete categories, semihypergroups and hypergroups have not free objects we will introduce t...
15 صفحه اولOn Alternation and the Union Theorem
Under the assumption P= Σ 2 , we prove a new variant of the Union Theorem of McCreight and Meyer for the class Σ 2 . This yields a union function F which is computable in time F (n) for some constant c and satisfies P = DTIME(F ) = Σ2(F ) = Σ p 2 with respect to a subfamily (S̃i) of Σ2-machines. We show that this subfamily does not change the complexity classes P and Σ 2 . Moreover, a padding co...
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chapter one is devoted to a moderate discussion on preliminaries, according to our requirements. chapter two which is based on our work in (24) is devoted introducting weighted semigroups (s, w), and studying some famous function spaces on them, especially the relations between go (s, w) and other function speces are invesigated. in fact this chapter is a complement to (32). one of the main fea...
15 صفحه اولOn FO quantifier alternation over words⋆
We show that each level of the quantifier alternation hierarchy within FO[<] on words is a variety of languages. We use the notion of condensed rankers, a refinement of the rankers defined by Weis and Immerman, to produce a decidable hierarchy of varieties which is interwoven with the quantifier alternation hierarchy – and conjecturally equal to it. It follows that the latter hierarchy is decid...
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ژورنال
عنوان ژورنال: Journal of Approximation Theory
سال: 1974
ISSN: 0021-9045
DOI: 10.1016/0021-9045(74)90064-1