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Viewing Version 1 of 'nested interval theorem'
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Title of object: nested interval theorem
Canonical Name: NestedIntervalTheorem
Type: Definition

Created on: 2007-08-06 08:11:45
Modified on: 2007-08-06 08:11:45

Creator: pahio
Modifier: stevecheng
Author: pahio

Classification: msc:26-00, msc:54C30

Preamble:

% this is the default PlanetMath preamble. as your knowledge
% of TeX increases, you will probably want to edit this, but
% it should be fine as is for beginners.

% almost certainly you want these
\usepackage{amssymb}
\usepackage{amsmath}
\usepackage{amsfonts}

% used for TeXing text within eps files
%\usepackage{psfrag}
% need this for including graphics (\includegraphics)
%\usepackage{graphicx}
% for neatly defining theorems and propositions
\usepackage{amsthm}
% making logically defined graphics
%\usepackage{xypic}

% there are many more packages, add them here as you need them

% define commands here

\theoremstyle{definition}
\newtheorem*{thmplain}{Theorem}
Content:

If
$$[a_1,\,b_1]\;\supseteq [a_2,\,b_2]\;\supseteq [a_3,\,b_3]\;\supseteq\ldots$$
is a sequence of nested closed intervals, then
\begin{align}
\bigcap_{n=1}^\infty [a_n,\,b_n] \neq \varnothing.
\end{align}
If also\, $\displaystyle\lim_{n\to\infty}(b_n-a_n) = 0$,\, then the union (1) consists of a unique real number.