Hear me out here. I tried to do \nless which I found online, however I was just given and undefined control sequence error message. What should I do?

  • 4
    You need to load amssymb for \nless.
    – moewe
    Sep 13, 2018 at 11:51
  • Thank you. I was using amsmath and I thought that would be enough. Sep 13, 2018 at 12:07
  • 2
    you may find \not \lt gives you what you are looking for
    – Henry
    Sep 13, 2018 at 14:13
  • The title of the question sounds weird. I'd recommend to change it to understand the question more easily. What about: What is the not less than operator in LaTeX?
    – Charlie
    Sep 18, 2018 at 16:43
  • When I come across a macro that is undefined, I often just come to this site and use the search feature on the macro name. If you can find a question or answer here where it is used, the MWE will always point you towards which package to load. Sep 18, 2018 at 17:46

1 Answer 1


Go to Detexify and draw what you want:

enter image description here

  1. the symbol is \nless
  2. you need \usepackage{amssymb}
  • 2
    Note that some fonts and their supporting .sty files already include the \nless symbol without having to load amssymb. Among these are Lucida Bright (\usepackage{lucidabr}) and MathTime Pro 2 (\usepackage{mtpro2}).
    – murray
    Aug 4, 2019 at 19:16
  • Is there a use case where this would be preferable to the "greater or equal" sign ?
    – Rphad
    Dec 25, 2020 at 20:48
  • @Rphad ? (I don't understand your comment)
    – Rmano
    Dec 25, 2020 at 21:52
  • In maths, saying that 3 is not < 2 is equivalent to saying 3 >= 2. So I wonder why one might use not < instead of >=
    – Rphad
    Dec 25, 2020 at 21:54
  • Ah, ok. That is probably a matter of style, personal preferences or similar things.
    – Rmano
    Dec 25, 2020 at 22:17

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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