共查询到20条相似文献,搜索用时 15 毫秒
1.
Olivier Esser 《Mathematical Logic Quarterly》2003,49(1):97-100
This is a study of the relative interpretability of the axiom of extensionality in the positive set theory. This work has to be considered in the line of works of R. O. Gandy, D. Scott and R. Hinnion who have studied the relative interpretability of the axiom of extensionality in set theories of Zermelo and Zermelo‐Fraenkel. 相似文献
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Paul Howard 《Mathematical Logic Quarterly》2007,53(3):247-254
Two theorems are proved: First that the statement “there exists a field F such that for every vector space over F, every generating set contains a basis” implies the axiom of choice. This generalizes theorems of Halpern, Blass, and Keremedis. Secondly, we prove that the assertion that every vector space over ?2 has a basis implies that every well‐ordered collection of two‐element sets has a choice function. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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John L. Bell 《Mathematical Logic Quarterly》2008,54(2):194-201
A weak form of intuitionistic set theory WST lacking the axiom of extensionality is introduced. While WST is too weak to support the derivation of the law of excluded middle from the axiom of choice, we show that bee.ng up WST with moderate extensionality principles or quotient sets enables the derivation to go through. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Adam M. Oberman. 《Mathematics of Computation》2005,74(251):1217-1230
This article considers the problem of building absolutely minimizing Lipschitz extensions to a given function. These extensions can be characterized as being the solution of a degenerate elliptic partial differential equation, the ``infinity Laplacian', for which there exist unique viscosity solutions.
A convergent difference scheme for the infinity Laplacian equation is introduced, which arises by minimizing the discrete Lipschitz constant of the solution at every grid point. Existence and uniqueness of solutions to the scheme is shown directly. Solutions are also shown to satisfy a discrete comparison principle.
Solutions are computed using an explicit iterative scheme which is equivalent to solving the parabolic version of the equation.
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Laurence Kirby 《Archive for Mathematical Logic》2008,47(2):143-157
This article defines a hierarchy on the hereditarily finite sets which reflects the way sets are built up from the empty set
by repeated adjunction, the addition to an already existing set of a single new element drawn from the already existing sets.
The structure of the lowest levels of this hierarchy is examined, and some results are obtained about the cardinalities of
levels of the hierarchy.
相似文献
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Omar De la Cruz Eric J. Hall Paul Howard Kyriakos Keremedis Jean E. Rubin 《Mathematical Logic Quarterly》2008,54(6):652-665
We study statements about countable and well‐ordered unions and their relation to each other and to countable and well‐ordered forms of the axiom of choice. Using WO as an abbreviation for “well‐orderable”, here are two typical results: The assertion that every WO family of countable sets has a WO union does not imply that every countable family of WO sets has a WO union; the axiom of choice for WO families of WO sets does not imply that the countable union of countable sets is WO. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Liu Pei-Dong Zheng Hong-Wen 《Proceedings of the American Mathematical Society》2000,128(12):3541-3545
In this note we prove that the generalized SRB measure of an Axiom A basic set is stable under random diffeomorphisms type perturbations.
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Sung-Hee Park 《Proceedings of the American Mathematical Society》2005,133(5):1463-1467
We give an example of an unbounded pseudoconvex Reinhardt domain in , which is Kobayashi complete but admits no local plurisubharmonic peak function at infinity.
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Let T:X → X be an Axiom A diffeomorphism,m the Gibbs state for a Hlder continuous function ɡ. Assume that f:X → Rd is a Hlder continuous function with ∫Xfdm = 0.If the components of f are cohomologously independent, then there exists a positive definite symmetric matrix σ2:=σ2 (f ) such that Sfn √ n converges in distribution with respect to m to a Gaussian random variable with expectation 0 and covariance matrix σ2 . Moreover, there exists a real number A > 0 such that, for any integer n ≥ 1,Π( m*( 1√ nS f n ),N (0,σ2 ) ≤A√n, where m*(1√ n Sfn)denotes the distribution of 1√ n Sfn with respect to m, and Π is the Prokhorov metric. 相似文献
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The regular extension axiom, REA, was first considered by Peter Aczel in the context of Constructive Zermelo‐Fraenkel Set Theory as an axiom that ensures the existence of many inductively defined sets. REA has several natural variants. In this note we gather together metamathematical results about these variants from the point of view of both classical and constructive set theory. 相似文献
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A. R. D. Mathias 《Annals of Pure and Applied Logic》2001,110(1-3):107-234
Saunders Mac Lane has drawn attention many times, particularly in his book Mathematics: Form and Function, to the system of set theory of which the axioms are Extensionality, Null Set, Pairing, Union, Infinity, Power Set, Restricted Separation, Foundation, and Choice, to which system, afforced by the principle, , of Transitive Containment, we shall refer as . His system is naturally related to systems derived from topos-theoretic notions concerning the category of sets, and is, as Mac Lane emphasises, one that is adequate for much of mathematics. In this paper we show that the consistency strength of Mac Lane's system is not increased by adding the axioms of Kripke–Platek set theory and even the Axiom of Constructibility to Mac Lane's axioms; our method requires a close study of Axiom H, which was proposed by Mitchell; we digress to apply these methods to subsystems of Zermelo set theory , and obtain an apparently new proof that is not finitely axiomatisable; we study Friedman's strengthening of , and the Forster–Kaye subsystem of , and use forcing over ill-founded models and forcing to establish independence results concerning and ; we show, again using ill-founded models, that proves the consistency of ; turning to systems that are type-theoretic in spirit or in fact, we show by arguments of Coret and Boffa that proves a weak form of Stratified Collection, and that is a conservative extension of for stratified sentences, from which we deduce that proves a strong stratified version of ; we analyse the known equiconsistency of with the simple theory of types and give Lake's proof that an instance of Mathematical Induction is unprovable in Mac Lane's system; we study a simple set theoretic assertion—namely that there exists an infinite set of infinite sets, no two of which have the same cardinal—and use it to establish the failure of the full schema of Stratified Collection in ; and we determine the point of failure of various other schemata in . The paper closes with some philosophical remarks. 相似文献
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D. I. Savel’ev 《Mathematical Notes》2007,81(5-6):716-719
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Horst Herrlich 《Mathematical Logic Quarterly》2003,49(3):323-324
It is shown that in ZF set theory the axiom of choice holds iff every non empty topological space has a maximal closed filter. 相似文献
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Pé ter Komjá th Saharon Shelah 《Proceedings of the American Mathematical Society》1996,124(11):3501-3505
It is consistent for every that and there is a function such that every finite set can be written in at most ways as the union of two distinct monocolored sets. If GCH holds, for every such coloring there is a finite set that can be written at least ways as the union of two sets with the same color.