I am using writelatex to write a paper and I need to type the semidirect product symbol...but for some reason, it keeps saying "error" and I can't see the semidirect product in the paper. I tried both \rtimes and \ltimes and both did not work. I searched the internet to see if there were other ways to type it using latex but I only found these two, and they both didn't work in writelatex...so I was wondering if anybody could help me with this...

  • 4
    Are you using the amssymb package?
    – kan
    Apr 26, 2013 at 10:27
  • 1
    And here goes a MWE: writelatex.com/158819zfcjtc
    – kan
    Apr 26, 2013 at 10:29
  • 4
    No, I'd think you'll have to load amsmath together with amssymb: \usepackage{amsmath, amssymb}.
    – kan
    Apr 26, 2013 at 10:34
  • 1
    The ams packages are distributed in several different families. Take a look at ftp.ams.org/pub/tex/doc/amsmath/amsldoc.pdf and ftp.ams.org/pub/tex/doc/amsfonts/amsfndoc.pdf to see what the amsmath and amssymb packages contain. Apr 26, 2013 at 10:43
  • 3
    @Artus amsmath provides many facilities for typesetting, such as alignment environments; amssymb provides scores of symbols; they are complementary, not alternative.
    – egreg
    Apr 26, 2013 at 11:03

1 Answer 1


You can use DeTeXify for finding out such things:

enter image description here

It also tells you that you need the amssymb package.

Not the answer you're looking for? Browse other questions tagged .