Advanced Calculus: Difference between revisions
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* Union of infinitely many closed sets can be open. | * Union of infinitely many closed sets can be open. | ||
* Intersection of infinitely many open sets can be closed. | * Intersection of infinitely many open sets can be closed. | ||
* <math>\{\}</math and <math>\mathbb{R}</math> are both open and closed | * <math>\{\}</math> and <math>\mathbb{R}</math> are both open and closed | ||
===Compact=== | ===Compact=== |