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| − | <div style="width: 70%; margin: 0 15% 1em 15%; text-align: center; background-color: #DEE6ED; padding: 0.5em; border: solid 1px #6699CC;">'''This article has been identified as being in conservapedia and is therefore classified under the heading worthless. This assement was made by the Icewedge inquisition.'''<br /><small>To go to a more factual encyclopedia go to wikipedia or even to uncyclopedia because even it has more content than CP.</small></div><includeonly>[[Category:Articles needing major improvement]]</includeonly> | + | The '''Urysohn lemma''' states: |
| | + | <blockquote> |
| | + | If ''A'', ''B'' are 2 disjoint, closed subsets of a [[normal space]] ''X'', then there exist a [[continuous function]] ''f'' : ''X'' → [0, 1], such that ''f(A)'' = 0 and ''f(B)'' = 1. |
| | + | </blockquote> |
| | + | The converse of the Urysohn lemma also holds. |
| | [[category: Topology]] | | [[category: Topology]] |