Talk:Bracket (mathematics)

Bracket (mathematics)
Okay. Is there any need for a fork of Bracket? I don't see any discussion on Talk:Bracket. Can you give me one good reason for not speedy deleting this or turning it into a redirect? --Aim Here 11:26, 14 May 2007 (UTC)

Yes Octovishier (talk) 14:11, 13 May 2021 (UTC)

Square Brackets as Parentheses
 The following is written regarding algebraic notations: "Square brackets are also often used in place of a second set of parentheses when they are nested, to provide a visual distinction. This usage is not technically correct, but is quite common."

I did not know it was incorrect to use square brackets. Could this please be elaborated as to why it is "not technically correct" and perhaps a cite a source to verify this. 24.49.35.99 (talk) 00:41, 6 March 2010 (UTC)


 * Beats me. I've never heard that it's incorrect either, and I use square brackets like that all the time. Since no source was given to support that claim, I just went ahead and deleted it. —Bkell (talk) 18:24, 6 March 2010 (UTC)

Recurring Numbers
Can we not also represent 0.999... as 0.(9)? This is what I read on the 0.999... page, and I think that it should be included here. I shan't add it, I'd like to see responses from the "old hands" first. Joseph Fyfield 06:59, 9 March 2011 (UTC)

Not international view. in intervals at least
In Poland, we use (a,b) when the interval doesn't include a nor b, and  when a and b are included. So we use angle brackets instead of your(american?) square brackets.


 * I shouldn't think the square brackets are solely an American custom: according to ISO 31-11, they were (and I assume they still are) an ISO standard, and it's said that Bourbaki uses (in a way) square brackets even for open intervals. — 2d37 (talk) 02:57, 10 April 2020 (UTC)

Double Bar Brackets
Could anyone more knowledgeable than me please add the meaning of double bar brackets? They look a little bit like this ||x||, sometimes one also finds this &#91;&#91;x&#93;&#93;


 * $$\|x\|$$ would most likely be the norm of $$x$$, and $$[\![x]\!]$$ might be the floor of $$x$$. — 2d37 (talk) 01:39, 25 March 2020 (UTC)

Square brackets for quadratic fields?
I encountered the notation Z[$\sqrt{−2}$] in the wild with insufficient context, and it took me quite a while to work out that it was referring to these. Anyone have any suggested wording that could be crafted for use here? 109.255.211.6 (talk) 23:11, 8 March 2021 (UTC)