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1. • CommentRowNumber1.
   • CommentAuthorlittlekuo
   • CommentTimeAug 14th 2020
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   Author: littlekuo
   Format: MarkdownItex[Proposition 2.26. (closure of a finite union is the union of the closures)](https://ncatlab.org/nlab/show/Introduction+to+Topology+--+1#ClosureOfAFiniteUnionIsUnionOfTheClosures) In the proof , it says: > "because if every neighbourhood of a point intersects all the $U_i$, then every neighbourhood intersects their union." maybe it should be "because if every neighbourhood of a point intersects some $U_i$, then every neighbourhood intersects their union."

   Proposition 2.26. (closure of a finite union is the union of the closures)

   In the proof , it says:

   “because if every neighbourhood of a point intersects all the $U_i$, then every neighbourhood intersects their union.”

   maybe it should be “because if every neighbourhood of a point intersects some $U_i$, then every neighbourhood intersects their union.”

2. • CommentRowNumber2.
   • CommentAuthorUrs
   • CommentTimeAug 14th 2020
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   Author: Urs
   Format: MarkdownItexYes, thanks for catching. I have fixed it now ([here](https://nforum.ncatlab.org/discussion/11623/introduction-to-topology-1/?Focus=86270#Comment_86270)).

   Yes, thanks for catching. I have fixed it now (here).