Lefschetz's principle
Lefschetz's principle
复制标题
莱夫谢茨原理
DOI:
10.1016/0021-8693(69)90117-3
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发表时间:
1969
期刊:
影响因子:
--
通讯作者:
P. Eklof
中科院分区:
文献类型:
--
作者:
J. Barwise;P. Eklof
In this paper we describe a language in which the statements of algebraic geometry can readily be cxpresscd and for which Lefschetz’s principle can be proved. We describe the language in detail and prove the mctamathematical results in Section 1. The results of Section 1 are applied to algebraic geometry in Section 2. In Section 3 WC make some brief historical remarks. We wish to express our appreciation to Professor Abraham Robinson for many interesting discussions during the course of this work. What WC call Lcfschetz’s principle’has been stated by Weil as follows ([II], p. 306):“f or ag ivcn value of the characteristicp, every result, involving only a finite number of points and of varieties, which has been proved for some choice of the universal domain remains valid without restriction; there is but one algebraic geometry of characteristic p for each value of p, not one algebraic geometry for each choice of the universal domain.” Weil says that a formal proof of this principle would require “a formal ‘metamathematical’characterization of the type of proposition” to which it applies;“this would have to depend upon the ‘metamathematical’ie logical analysis of all our definitions.” In this paper we attempt to carry out this program. Thus in contrast to previous metamathcmatical formulations of the Lefschetz principle which arose from general logical considerations (see Section 3) our starting point has been an analysis of the definitions of algebraic geometry. The result is a language which from the logical point of view is somewhat complex (it is a higher-order, infinitary language), but which is closely akin to the natural language of algebraic geometry. Thus, for example, in models of the language, variables standing for ideals range over sets of polynomials, and variables standing for varieties in affine n-space range over sets of n-tuples.