不确定性的困惑与NP理论分享 http://blog.sciencenet.cn/u/liuyu2205 平常心是道

博文

康托尔论对角线法的论文 - “关于所有实数代数集合的一个属性”

已有 1768 次阅读 2023-5-26 02:49 |个人分类:Paul Jorion的书译文|系统分类:科研笔记

康托尔(Georg Cantor1845 - 1918)关于对角线论证的著名德语论文首次发表在1890年德国数学联盟(Deutsche Mathematiker-Vereinigung)的期刊上

一,英文译文

https://web.archive.org/web/20060423090728/http://uk.geocities.com/frege%40btinternet.com/cantor/diagarg.htm

In the paper entitled "On a property of a set [Inbegriff] of all real algebraic numbers" (Journ. Math. Bd. 77, S. 258), there appeared, probably for the first time, a proof of the proposition that there is an infinite manifold, which cannot be put into a one-one correlation with the totality [Gesamtheit] of all finite whole numbers 1, 2, 3, …, v, …, or, as I am used to saying, which do not have the power (Mächtigkeit) if the number series 1, 2, 3, …, v, ….  From the proposition proved in § 2 there follows another, that e.g. the totality (Gesamtheit) of all real numbers of an arbitrary interval (a ... b) cannot be arranged in the series :

w1 w2, …, w, …

However, there is a proof of this proposition that is much simpler, and which does not depend on considering the irrational numbers.

Namely, let m and n be two different characters, and consider a set [Inbegriff] M of elements :

E = (x1, x2, … , xv, …)

which depend on infinitely many coordinates x1, x2, … , xv, …, and where each of the coordinates is either m or w.  Let M be the totality [Gesamtheit] of all elements E.

To the elements of M belong e.g. the following three:

EI  = (m, m, m, m, … ),

EII = (w, w, w, w, … ),

EIII = (m, w, m, w, … ).

I maintain now that such a manifold [Mannigfaltigkeit] M does not have the power of the series 1, 2, 3, …, v, ….

This follows from the following proposition:

"If E1, E2, …, Ev, … is any simply infinite [einfach unendliche] series of elements of the manifold M, then there always exists an element E0 of M, which cannot be connected with any element Ev. »

For proof, let there be

E1 = (a1.1, a1.2, … , a1,v, …)

E2 = (a2.1, a2.2, … , a2,v, …)

Eu = (au.1, au.2, … , au,v, …)

...

where the characters au,v are either m or w.  Then there is a series b1, b2, … bv,…, defined so that bv is also equal to m or w but is different from av,v.

Thus, if av,v = m, then bv = w.

Then consider the element

E0 = (b1, b2, b3, …)

of M, then one sees straight away, that the equation

E0 = Eu

cannot be satisfied by any positive integer u, otherwise for that u and for all values of v.

bv = au,v

and so we would in particular have

bu = au,u

which through the definition of  bv is impossible.  From this proposition it follows immediately that the totality of all elements of M cannot be put into the sequence [Reihenform]: E1, E2, …, Ev, … otherwise we would have the contradiction, that a thing [Ding] E0 would be both an element of M, but also not an element of M.

二,中文译文

在题为关于所有实数代数的集合的一个属性(On a property of a set of all real algebraic numbersJourn. Math. Bd. 77, S. 258)中,可能第一次出现了命题的证明,即有一个无限的流形,或者如我习惯说的,数列123...v....,的幂集,它不能与所有整数123...v...形成一一对应的关系。 从第2节中证明的命题得出,例如,任意区间(a ... b)的所有实数的总体(Gesamtheit)不能被排列成数列:

w1 w2, …, w, …

然而,这个命题有一个更简单的证明,它不依赖于考虑无理数。

也就是说,让mn是两个不同的字符,并考虑一个元素的集合M

E = (x1, x2, … , xv, …)

这取决于无限多的坐标x1x2xv...,其中每个坐标都是mw。让M是所有元素E的总体。

M的元素中,例如属于以下三个:

EI  = (m, m, m, m, … ),

EII = (w, w, w, w, … ),

EIII = (m, w, m, w, … ).

我现在指出,这样一个流形M不具有系列123...vpower..

由以下命这题得出:

"如果E1E2...Ev...是流形M的任何简单无限元素系列,那么M中总是存在一个元素E0,它不能与任何元素Ev连接。"

为了证明这一点,让我们有

E1 = (a1.1, a1.2, … , a1,v, …)

E2 = (a2.1, a2.2, … , a2,v, …)

Eu = (au.1, au.2, … , au,v, …)

...

然后有一个系列b1, b2, ... bv, ...,定义为bv也等于mw,但与av,v不同。

因此,如果av,v=m,那么bv=w

然后考虑M的元素:

E0 = (b1, b2, b3, …)

那么我们可以直接看到,方程:

E0 = Eu

不能被任何正整数u所满足,否则对该u和所有v的值来说都是如此。

bv = au,v

我们将特别有:

bu = au,u

而根据bv的定义,这是不可能的。从这个命题立即可以看出,M的所有元素的整体不能被放入序列: E1, E2, ..., Ev, ...,否则我们就会产生矛盾,即一个事物E0既是M的一个元素,但也不是M的一个元素。




https://blog.sciencenet.cn/blog-2322490-1389428.html

上一篇:关于康托尔理论的争议
下一篇:图灵文章《论可计算数及其在判定问题上的应用》的第9章译文
收藏 IP: 77.201.68.*| 热度|

2 尤明庆 杨正瓴

该博文允许注册用户评论 请点击登录 评论 (0 个评论)

数据加载中...
扫一扫,分享此博文

Archiver|手机版|科学网 ( 京ICP备07017567号-12 )

GMT+8, 2024-11-22 15:28

Powered by ScienceNet.cn

Copyright © 2007- 中国科学报社

返回顶部