Difference between revisions of "Dense"

m
m
 
Line 1: Line 1:
Let ''X'' be a topological space and ''S'' a subspace. Then ''S'' is '''dense''' in ''X'' if, for any <math>x\in X</math> and any [[open set|open]] neighborhood <math>U\ni x</math>, <math>U\cap S\neq\varnothing</math>. For example, the [[rational number]]s are dense in the [[real number]]s.
+
{{stub}}
  
{{stub}}
+
 
 +
Let <math>X</math> be a [[topological space]] and <math>S</math> be a [[subspace]] of <math>X</math>. Then <math>S</math> is '''dense''' in <math>X</math> if, for any <math>x\in X</math> and any [[open set|open]] neighborhood <math>U\ni x</math>, <math>U\cap S\neq\varnothing</math>. For example, the [[rational number]]s are dense in the [[real number]]s.

Latest revision as of 15:42, 18 August 2006

This article is a stub. Help us out by expanding it.


Let $X$ be a topological space and $S$ be a subspace of $X$. Then $S$ is dense in $X$ if, for any $x\in X$ and any open neighborhood $U\ni x$, $U\cap S\neq\varnothing$. For example, the rational numbers are dense in the real numbers.