Applications of the low-basis theorem in arithmetic

Author(s):  
P. Clote
Keyword(s):  
2014 ◽  
Vol 400 ◽  
pp. 8-16 ◽  
Author(s):  
Paul Apisa ◽  
Benjamin Klopsch
Keyword(s):  

1977 ◽  
Vol 29 (5) ◽  
pp. 1069-1071 ◽  
Author(s):  
L. Drewnowski

W. J. Stiles showed in [10, Corollary 4.5] that Banach's weak basis theorem fails in the spaces lp, 0 < p < 1. Then, J. H. Shapiro [9] indicated certain general classes of non-locally convex F-spaces with the same property, and asked whether the weak basis theorem fails in every non-locally convex F-space with a weak basis. Our purpose is to answer this question in the affirmative. In [3] we observed that, essentially, the only case that remained open is that of an F-space with irregular basis (en), i.e. such that snen →0 for any scalar sequence (sn).


1966 ◽  
Vol 18 ◽  
pp. 969-973
Author(s):  
C. J. Everett

The basis theorem for directed graphs is, in effect, a result on weakly ordered sets, and, in §1, a proof is given, based on Zorn's lemma, that generalizes, and perhaps clarifies the exposition in (1, Chapter 2). In §2, a graph G* is defined, on an arbitrary collection Q of non-void subsets of a set X (which includes all its one-element subsets), in such a way that the partitions of X into Q-sets correspond to the kernels of G*. Applied to the collection Q of non-null internally stable subsets of a graph G without loops, this identifies the chromatic number of G with the least cardinal number of any kernel of G*.


1979 ◽  
Vol 86 (3) ◽  
pp. 212-212
Author(s):  
William C. Waterhouse
Keyword(s):  

1980 ◽  
Vol 29 (3) ◽  
pp. 229-233 ◽  
Author(s):  
Joel Berman
Keyword(s):  

1950 ◽  
Vol s1-25 (4) ◽  
pp. 259-264 ◽  
Author(s):  
J. W. S. Cassels ◽  
G. E. Wall
Keyword(s):  

1982 ◽  
Vol 47 (2) ◽  
pp. 388-394 ◽  
Author(s):  
Ashok Maitra

A recent result of J.P. Burgess [1] states:Theorem 0. Let F be a multifunction from an analytic subset T of a Polish space to a Polish space X. If F is Borel measurable, Graph(F) is coanalytic in T × X and F(t) is nonmeager in its closure for each t Є T, then F admits a Borel measurable selector.The above result unifies and significantly extends earlier results of H. Sarbadhikari [8], S.M. Srivastava [9] and G. Debs (unpublished). The reader is referred to [1] for details.The aim of this article is to give an effective version of Theorem 0. We do this by proving a basis theorem for Π11 sets which are nonmeager in their closure and satisfy a local version of the measurability condition in Theorem 0. Our basis theorem generalizes a well-known result of P.G. Hinman [4] and S.K. Thomason [10] (see also [5] and [7, 4F.20]). Our methods are similar to those used by A. Louveau to prove that a , σ-compact set is contained in a , σ-compact set (see [7, 4F.18]).The paper is organized as follows. §2 is devoted to preliminaries. In §3, we prove the basis theorem and deduce as a consequence an effective version of Theorem 0. We show in §4 how our methods can be used to give alternative proofs of some known results.Discussions with R. Barua, B.V. Rao and V.V. Srivatsa are gratefully acknowledged. I am indebted to J.P. Burgess for drawing my attention to an error in an earlier draft of this paper.


1997 ◽  
Vol 29 (2) ◽  
pp. 150-158 ◽  
Author(s):  
K. A. Brown ◽  
K. R. Goodearl

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