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1. • CommentRowNumber1.
   • CommentAuthorMike Shulman
   • CommentTimeJul 21st 2017
   • PermaLink
   Author: Mike Shulman
   Format: MarkdownItexIt seems that Peter recently deleted the example > The collection of "admissible" ("[[open map|open]]") morphisms in a [[geometry (for structured (∞,1)-toposes)]]. from [[two-out-of-three]]. Peter, I think this sort of edit should be announced at the forum. However, just looking at the page [[geometry (for structured (∞,1)-toposes)]] it seems to me that the deletion was correct: the definition of "geometry" only asks for 2/3 of 2-out-of-3 (closure under composition and *left* cancellability). Urs, is that right?

   It seems that Peter recently deleted the example

   The collection of “admissible” (“open”) morphisms in a geometry (for structured (∞,1)-toposes).

   from two-out-of-three. Peter, I think this sort of edit should be announced at the forum. However, just looking at the page geometry (for structured (∞,1)-toposes) it seems to me that the deletion was correct: the definition of “geometry” only asks for 2/3 of 2-out-of-3 (closure under composition and left cancellability). Urs, is that right?

2. • CommentRowNumber2.
   • CommentAuthorPeter Heinig
   • CommentTimeJul 21st 2017
   • (edited Jul 21st 2017)
   • PermaLink
   Author: Peter Heinig
   Format: MarkdownItexRe # 1. Mike, first or all, thanks for being so careful. Let us briefly leave aside that Mike thinks the deletion warranted. I'll give you my immediate reaction: surprise, puzzlement and a little fear. I agree that my name is displayed in the history, but * the person writing this lines *does not remember making this edit* * the person writing this lines *would not make such a change without notifying the nForum* I therefore see no reason for apologizing. I have little technical knowledge of IP-address-technology, but just in the unlikely case *that someone else has something meaningful to say on this technical issue*: is the "technological fingerprint" of this edit meaningfully different from others signed by my name? To sum up, this is probably some *random issue* of some sort or the other, and we should not make much of it.

   Re # 1.

   Mike, first or all, thanks for being so careful.

   Let us briefly leave aside that Mike thinks the deletion warranted.

   I’ll give you my immediate reaction: surprise, puzzlement and a little fear.

   I agree that my name is displayed in the history, but

   • the person writing this lines does not remember making this edit

   • the person writing this lines would not make such a change without notifying the nForum

   I therefore see no reason for apologizing.

   I have little technical knowledge of IP-address-technology, but just in the unlikely case that someone else has something meaningful to say on this technical issue: is the “technological fingerprint” of this edit meaningfully different from others signed by my name?

   To sum up, this is probably some random issue of some sort or the other, and we should not make much of it.

3. • CommentRowNumber3.
   • CommentAuthorUrs
   • CommentTimeJul 21st 2017
   • PermaLink
   Author: Urs
   Format: MarkdownItex> Urs, is that right? Yes, certainly. Not sure what I was thining, back on 7th Feb 2011, when I wrote this [here](https://ncatlab.org/nlab/revision/two-out-of-three/1).

   Urs, is that right?

   Yes, certainly. Not sure what I was thining, back on 7th Feb 2011, when I wrote this here.

4. • CommentRowNumber4.
   • CommentAuthorMike Shulman
   • CommentTimeJul 21st 2017
   • PermaLink
   Author: Mike Shulman
   Format: MarkdownItexThe change was made from exactly the same IPv6 address as [this one](https://ncatlab.org/nlab/revision/operation/2), so it seems quite likely that it was indeed you. We all forget things on occasion. Sometimes I make an edit and mean to notify the nforum about it, but get involved in something else before I get around to it and then forget to get back to it. Another possibility is that you were editing the page for some other reason (or with some other reason in mind), or even just going to the "edit" view to copy something from the source code, and accidentally deleted the line without meaning to.

   The change was made from exactly the same IPv6 address as this one, so it seems quite likely that it was indeed you. We all forget things on occasion. Sometimes I make an edit and mean to notify the nforum about it, but get involved in something else before I get around to it and then forget to get back to it. Another possibility is that you were editing the page for some other reason (or with some other reason in mind), or even just going to the “edit” view to copy something from the source code, and accidentally deleted the line without meaning to.