Talk:Subset

message: The section "⊂ and ⊃ symbols" only mentions the symbols ⊊ and ⊋ as something some authors prefer not to use. The reference there does not mention these symbols. It would be useful to find a positive reference for authors that do prefer to use ⊊ and ⊋ for proper sub/supersets, and use ⊂ and ⊃ where the two sets may be equal.  — Preceding unsigned comment added by Kopretinka (talk • contribs) 10:14, 27 November 2017 (UTC)
replies: text: There's a whole list at Wikipedia talk:WikiProject Mathematics/Conventions#Literature survey.  That's part of what I would call an obsolete discussion from more than a decade ago, but should be a good resource to find authors who do various things.  --Trovatore (talk) 19:27, 27 November 2017 (UTC)
thread_title:  Symbols ⊊ and ⊋ 

message: I've found a book that uses ⊂,⊃ instead of ⊊,⊋, and introduces the secondary notation as not very common. I don't know how to do citations but the book is "Mathematical Proofs: A Transition to Advanced Mathematics 3rd Edition by Chartrand". If someone could add this to the article it'd be greatly appreciated. — Preceding unsigned comment added by 130.101.12.167 (talk • contribs) 22:27, 2 September 2021 (UTC)
replies: text: OK, it's true that ⊊,⊋ are not really very common, but that's in part because the notion of strict subset is less important than the notion of subset.  Lots of sources use ⊂ for the more important notion, the one sometimes notated \subseteq.  This should be discussed somewhere, but without suggesting that ⊂ normally means strict subset, which isn't true. --Trovatore (talk) 01:47, 3 September 2021 (UTC)
thread_title:  Better sourcing for subset notation 

message: Hipo 175.176.92.201 (talk) 11:14, 31 August 2022 (UTC)
thread_title:  Hi 

message: In the "Examples of Subsets" section:
* The set A = {1, 2} is a proper subset of B = {1, 2, 3}, thus both expressions A \subseteq B and A \subsetneq B are true.
* The set D = {1, 2, 3} is a subset (but  a proper subset) of E = {1, 2, 3}, thus D \subseteq E is true, and D \subsetneq E is not true (false).
* I think \subseteq that I bolded should be \subset. Otherwise both proper and improper subsets are denoted by the same symbol.
* Can someone review this, I'm not a mathematician.
Zeyn1 (talk) 11:30, 19 October 2023 (UTC)
replies: text:  There is nothing here that needs to be fixed.  In the first example, A \subseteq B and A \subsetneq B are both true, as stated, because A is both a subset of B and a proper subset of B.  (There is no such thing as an "improper subset".) --Trovatore (talk) 14:47, 20 October 2023 (UTC)
replies: text:  Oh, I just realized what you might mean.  Are you saying \subseteq and \subsetneq look the same to you visually?  Look closer.  The \subsetneq symbol has a cross through the line on the bottom.  Admittedly it can be a little hard to see sometimes. --Trovatore (talk) 14:59, 20 October 2023 (UTC)

text:  As an aside, does anyone know a single LaTeX command to get something like \stackrel{\subset}{\ne}?  There's a symbol that looks a bit like that, but better proportioned, that's sometimes used, and it's easier to see the not-equals part than in \subsetneq.  Could potentially be described in the article, or even used in it.  But I haven't been able to find such a thing. --Trovatore (talk) 20:04, 20 October 2023 (UTC)

text:  Ah, here it is: \subsetneqq.  Honestly I think that's much clearer to read. --Trovatore (talk) 20:09, 20 October 2023 (UTC)
thread_title:  About $\subseteq and \subset$