Description: Lemma for hauspwpwdom . Points in the closure of a set in a Hausdorff space are characterized by the open neighborhoods they extend into the generating set. (Contributed by Mario Carneiro, 28-Jul-2015)
Ref | Expression | ||
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Hypotheses | hauspwpwf1.x | |
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hauspwpwf1.f | |
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Assertion | hauspwpwf1 | |