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1. • CommentRowNumber1.
   • CommentAuthorUrs
   • CommentTimeMay 5th 2017
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   Author: Urs
   Format: MarkdownItexAt _[[limits and colimits by example]]_ an entry for _[[Kuratowski pair]]_ was requested, so I created it. The place where this should really be linked to is the entry _[[ordered pair]]_, so I added a link there. Also, I made that entry mention _[[Cartesian product]]_, which it didn't.

   At limits and colimits by example an entry for Kuratowski pair was requested, so I created it. The place where this should really be linked to is the entry ordered pair, so I added a link there. Also, I made that entry mention Cartesian product, which it didn’t.

2. • CommentRowNumber2.
   • CommentAuthorTobyBartels
   • CommentTimeMay 8th 2017
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   Author: TobyBartels
   Format: MarkdownItexI corrected your definition from $\{a, \{a,b\}\}$ to $\{\{a\}, \{a,b\}\}$. The former *can* be used, but it is trickier (it requires the axiom of foundation to prove the fundamental theorem), and it\'s not what Kuratoswki used.

   I corrected your definition from to . The former can be used, but it is trickier (it requires the axiom of foundation to prove the fundamental theorem), and it's not what Kuratoswki used.

3. • CommentRowNumber3.
   • CommentAuthorUrs
   • CommentTimeMay 8th 2017
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   Author: Urs
   Format: MarkdownItexOh, okay. Hm, why is that?

   Oh, okay. Hm, why is that?