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I'm currently trying to write over/under an implies arrow in LaTeX (in math mode):

\implies_{text}

This places the text lower, but next to the arrow, not below it. How can I get it below the arrow?

Ludovic C.
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Femaref
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1 Answers1

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You can use \xRightarrow[below]{above} from the mathtools (or extpfeil) package or \xLongrightarrow[below]{above} from extarrows. (Have a look at “How to look up a math symbol?” for ideas how you can easily find a particular symbol.)

If you want to keep the the same arrow length as implies, you can use \underset and \overset from amsmath, e.g. \underset{below}{\implies}, or maybe \underset{\mathclap{below}}{\implies} (\mathclap makes it so that “below” doesn’t introduce extra vertical space if it is longer than the arrow. It is included in the immensely useful mathtools package).

Community
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Caramdir
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  • Sadly, the proposed arrow looks different than the implies arrow, so it wouldn't fit with the rest of the equations :/ thanks for your help though. – Femaref Nov 09 '10 at 19:35
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    @femaref Except for the length they look exactly the same on my system. Do you want the length to stay constant? – Caramdir Nov 09 '10 at 19:39
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    the second thing helped me. For you, comparision of the two arrows: http://www.abload.de/img/arrows_zoomednbxj.png and http://www.abload.de/img/arrowsrbfs.png – Femaref Nov 09 '10 at 19:49
  • @femaref except for the length and bad rendering (which should go away when printed -- there is only supposed to be one black line without that gray fuzziness) they look the same to me. – Caramdir Nov 09 '10 at 19:53
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    \underset FTW. And I need to learn more about mathtools. – Matthew Leingang Nov 09 '10 at 19:56
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    @Femaref: You are using 12pt, aren't you? You might want to have a look at this question if you want the arrows look better. – Hendrik Vogt Nov 09 '10 at 21:33