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A question for English speakers. When using (or reading) the symbol $\setminus$ to denote set difference —

$A\setminus B=\{x\in A|x\notin B\}$

— how do you pronounce it?

If you please, indicate in a comment on your answer what region you're from (what dialect you have).


This is a poll question. Please do not repeat answers! Rather, upvote an answer if you pronounce the symbol the same way the answerer does, and downvote it not at all. Please don't upvote answers for other reasons. Thanks!

  • 0
    I tend to pronounce it "$A$ delete $B$."2015-09-04

10 Answers 10

25

$A$ minus $B$ seems to be the natural way.

  • 0
    As an English speaking programmer (not mathematician) that's how I'd say this2012-02-28
15

I usually say "A without B," but it depends on my mood that day

  • 0
    This is the one I use. (US Midwest)2012-07-03
8

No one's mentioned "$A$ take away $B$" yet.

  • 0
    That doesn't sound very mathematical. +12013-06-14
5

I pronounce $A \setminus B$ just as the latex code: $A$ setminus $B$.

  • 4
    I should perhaps stop writing this as "A \backslash B"...2012-02-28
2

Prologue: I usually try NOT to pronounce math symbols or expressions or say it loud in mind as (claimed in folklore) that internal reading seems to hinder 'speed reading' or comprehension. (Note: I am hugely influenced by Eastern arts so may be there is some truth to that. (Meta-note: Feel free to comment on it if you disagree))

Vote status: Upvoted for making me look up some links.

Answer:

2

In situations such as the theory of automorphic forms/functions, the expression $A\backslash B$ means "$B$ left mod $A$", not set-complement. It is pronounced that way: "B left-mod A".

This is necessary because there are quotients on the right also, which interact with these. It amazes me how much trouble it is to get students to "recover from" thinking that "backslash" could only mean "set complement". I say to them "why not just write '-' for set complement?".

The literature on automorphic what's-its is full of left quotients, notated $A\backslash B$.

1

Complement of B in A for A-B or sometime A difference B

This is more self explaining way to say.. I feel!

  • 0
    This is what seems to me the right way!2012-02-28
1

A less B.............................

  • 0
    This is what I was taught (in Ireland).2012-02-28
1

I say any of the following (it varies):

"A not B"

"A slash B"

and when I am trying to be clear

"The complement of B in A"

0

I say "A slash B".${}{}{}{}{}{}{}{}$

  • 0
    I guess there's not too much confusion between this and $A/B$, A modulo B :P2012-02-28