For anyone who uses ¡ (inverted exclamation mark) in a mathematical context, how do you pronounce it?

Background: I have privately been using ¡ in a couple of notations for a while, and am considering using it in a paper. One of my reservations about doing so is pronouncability: it isn’t standardly used for anything in the areas I work in, so if I use it in print, I’ll give a suggested pronunciation (incidentally, something I wish more authors would do when introducing notations for which there’s not an obvious/established reading).

The only existing usage I have found mentioned is as an old (?obsolete) notation for subfactorial. But, as an easily recognisable and available symbol, I guess it has probably been co-opted by other mathematicians on occasion.

For what it’s worth, I pronounce it to myself as “gnab”.

  • 2
    $\begingroup$ Unless I misunderstand, couldn't the (mathematical) pronunciation be more related to the operation it represents and not the punctuation mark itself. For example, we pronounce $5!$ as "five factorial", not "five exclamation mark" or "five bang". We pronounce $\nabla f$ as "del eff" (although I think I might have heard some pronounce it "nabla eff"). $\endgroup$
    – mhum
    Jan 14, 2016 at 2:01
  • 1
    $\begingroup$ What's its name in Spanish? Probably there are also colloquial Spanish names as well. $\endgroup$ Jan 14, 2016 at 3:17
  • 5
    $\begingroup$ GNAB = GNAB, Not A Bang $\endgroup$ Jan 14, 2016 at 3:51
  • 1
    $\begingroup$ Does it appear before the main actor or after? As subscript or superscript? $\endgroup$
    – Lubin
    Jan 14, 2016 at 5:10
  • 2
    $\begingroup$ I agree with mhum. For example, in my field ! is often pronounced "shriek" and ¡ is, in a similar context, pronounced "antishriek." $\endgroup$ Jan 14, 2016 at 5:27


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