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

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