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I know it's possible to have \xrightarrow (text), but if I try to do \xRightarrow (text) I get an error each time. Does anybody know if it's a syntax error or if there is a other way to produce the \Rightarrow with text above?

Paul Wintz
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Niels Sønderbæk
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3 Answers3

74

enter image description here

Just taking the definition of \xrightarrow and replacing r by R :

\documentclass{article}
\usepackage{amsmath}

\makeatletter
\newcommand{\xRightarrow}[2][]{\ext@arrow 0359\Rightarrowfill@{#1}{#2}}
\makeatother


\begin{document}


% To create a single arrow with text above, use lowercase "r".
$\xrightarrow{\mathit{hello}}$


% To create a double arrow with text above, use uppercase "R".
$\xRightarrow{\mathit{hello}}$


\end{document}
Paul Wintz
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David Carlisle
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    oh, please at least make that \mathit{hello} to get rid of the obnoxious math kerning. – barbara beeton Dec 01 '12 at 19:19
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    As I posted I felt your pain but I had to dash:-) – David Carlisle Dec 01 '12 at 20:52
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    how do you choose the single arrow when making the command? copy pasting your code (that has no explanation) yields the double arrow. – Charlie Parker May 29 '20 at 20:02
  • @CharlieParker I'm not sure I understand your question, my answer shows two arrows, the single one \xrightarrow is a standard command from amsmath just shown for comparison, and the double arrow version with capital R which is defined here. – David Carlisle May 29 '20 at 20:41
52
\documentclass{article}
\usepackage{mathtools}
\begin{document}

$\xrightarrow{\text{hello}}$
$\xRightarrow{\text{hello}}$

\end{document}

enter image description here

Lorents
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    Why the difference in arrow lengths? The head of the double arrow is under "o" of hello, while "hello" is entirely above the shaft of the single arrow. – Joshua Taylor Sep 01 '14 at 14:59
  • This has now been corrected in mathtools (and in the image above). – Lorents Jul 04 '23 at 10:52
10

You can also use underset and overset:

$\underset{\text{hello}} \longrightarrow$

$\overset{\text{hello}} \longrightarrow$

$\underset{\tiny\text{hello}} \longrightarrow$

$\overset{\tiny\text{hello}} \longrightarrow$
Bill Moore
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