Displaying similar documents to “On powers of Lindelöf spaces”

About the decision of reachability for register machines

Véronique Cortier (2002)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

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We study the decidability of the following problem: given p affine functions f 1 , ... , f p over ℕ k and two vectors v 1 , v 2 ∈ ℕ k , is v 2 reachable from v 1 by successive iterations of f 1 , ... , f p (in this given order)? We show that this question is decidable for p = 1 , 2 and undecidable for some fixed p .

Property D and pseudonormality in first countable spaces

Alan S. Dow (2005)

Commentationes Mathematicae Universitatis Carolinae

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In answer to a question of M. Reed, E. van Douwen and M. Wage [vDW79] constructed an example of a Moore space which had property D but was not pseudonormal. Their construction used the Martin’s Axiom type principle P ( c ) . We show that there is no such space in the usual Cohen model of the failure of CH.

Characterizations of spreading models of l 1

Persephone Kiriakouli (2000)

Commentationes Mathematicae Universitatis Carolinae

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Rosenthal in [11] proved that if ( f k ) is a uniformly bounded sequence of real-valued functions which has no pointwise converging subsequence then ( f k ) has a subsequence which is equivalent to the unit basis of l 1 in the supremum norm. Kechris and Louveau in [6] classified the pointwise convergent sequences of continuous real-valued functions, which are defined on a compact metric space, by the aid of a countable ordinal index “ γ ”. In this paper we prove some local analogues of the above Rosenthal...