Googling this question has proved somewhat useless, so the ¬ symbol:

  • What is it for?
  • What is is called?
  • Is it used in any programming languages?

closed as off-topic by amon, gnat, Telastyn, Arseni Mourzenko, user40980 Jul 19 '15 at 21:26

  • This question does not appear to be about software engineering within the scope defined in the help center.
If this question can be reworded to fit the rules in the help center, please edit the question.

  • 1
    That character is U+00AC NOT SIGN and is one of the many notations for logical negation – amon Jul 19 '15 at 18:49
  • 5
    I'm voting to close this question as off-topic because it is not about software development concepts as explained in the help center. – amon Jul 19 '15 at 18:50
  • 1
    It's on a standard UK 101 keyboard, top left with the back tick ` ` ` and the broken pipe ¦. – BanksySan Jul 19 '15 at 19:26
  • 2
    Wikipedia has redirects for many unicode symbols. ¬. You can also see this with things like 🍩. While google's search doesn't do a good job with this character, one should try pasting it into Wikipedia's search. They have many redirects for single unicode characters set up. – user40980 Jul 20 '15 at 2:23
  • 1
    Used to break long statements in app script alvinalexander.com/mac-os-x/… – Maxim Veksler May 15 '16 at 9:53

The only use I've seen for the ¬ symbol is to represent negation in the context of formal logic. For instance, if P is the proposition "It will rain today", then ¬P is the proposition "It will not rain today." I've also seen ~ used for this.

I don't believe it has an actual name other than "negation symbol". Normally it's read as "not".

As far as I know, in programming this symbol has no special meaning, at least not in any mainstream languages I've used.

  • Some programming languages accept UTF8 characters as names or user-defined operators. – Basile Starynkevitch Jul 19 '15 at 19:17
  • Why is negation symbol not an "actual name"? After all, we call ! exclamation point and ? question mark. And those are perfectly fine names. – Brandin Jan 26 '16 at 19:42
  • REXX uses ¬ for logical not and in operators like ¬=, ¬>, etc. Most implementation also allow `\` because many keyboards lack a ¬ key. I'm not sure that it can be considered a mainstream language, though. – mrb Aug 8 '16 at 13:33
  • PL/1 (developed in the late 1960s) used the ¬ symbol for not. Having used PL/1 for many years I still think of this as the not symbol – Kickstart Jul 6 '17 at 10:53
  • AppleScript uses ¬ as the line-continuation symbol, to split long commands into multiple lines, like \ in bash script. – Chad von Nau Jun 30 '18 at 22:39

Not the answer you're looking for? Browse other questions tagged or ask your own question.