摘要:

AbstractWe show that the Axiom of Choice is equivalent to each of the following statements: (i) A product of closures of subsets of topological spaces is equal to the closure of their product (in the product topology); (ii) A product of complete uniform spaces is complete.

ISSN:0942-5616    

DOI:10.1002/malq.19920380152

出版商:WILEY‐VCH Verlag Berlin GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractA simultaneous semantical and syntactical reduction is given for the satisfiability respectively finite satisfiability of first order formulas. We choose ∀∃∀∞(0, 1) as conservative reduction class and allow only formulas out of ∀∃∀∞(0, 1) having a simple set theoretical model if they are satisfiable at all. With the same method we get a spectral representation of any ϱ‐ary enumerable respectively coenumerable predicate by a formula

ISSN:0942-5616    

DOI:10.1002/malq.19920380153

出版商:WILEY‐VCH Verlag Berlin GmbH    

年代:1992

数据来源: WILEY

ISSN:0942-5616    

DOI:10.1002/malq.19920380154

出版商:WILEY‐VCH Verlag Berlin GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractWe consider two‐sorted theories of vector spaces and prove a criterion for the assertion that such a theory allows elimination of quantifiers over vector variable

ISSN:0942-5616    

DOI:10.1002/malq.19920380155

出版商:WILEY‐VCH Verlag Berlin GmbH    

年代:1992

数据来源: WILEY

ISSN:0942-5616    

DOI:10.1002/malq.19920380101

出版商:WILEY‐VCH Verlag Berlin GmbH    

年代:1992

数据来源: WILEY