Suppose I have a map AB which is an isomorphism. I'd like to represent this as something that looks like \rightarrow with \simunder it. I could try \underset{}_{}, but is there already a ready made symbol?

I couldn't find the symbol using Detexify, nor in the comprehensive list of LaTeX symbols.

  • 8
    You want the \sim under the \to? Odd. I don't think I've ever seen an isomorphism written like that. – TH. Oct 26 '10 at 2:38

Theoretically, you could use \xrightarrow[\sim]{} (from amsmath) or \xlongrightarrow[\sim]{} (from extarrows). Both look horrible though. The \sim on top of the arrow (like \xlongrightarrow{\sim}) looks somewhat better.

Unicode defines ⥴ (U+2974 RIGHTWARDS ARROW ABOVE TILDE OPERATOR), which you can use in case you run Xe/LuaLaTeX with unicode-math (either directly or with the \rightarrowsimilar alias). There are also ⥱ (\equalrightarrow), ⥲ (\similarrightarrow), ⥳ (\leftarrowsimilar), ⥵ (\rightarrowapprox) and other strange things.

| improve this answer | |
  • Thanks a lot for the comments! For me \xrightarrow{\sim} is quite enough. – qui_vadis Oct 26 '10 at 19:53

A bit of adjustment of the spacing may help. For example, with

  \xrightarrow[\raisebox{0.25 em}{\smash{\ensuremath{\sim}}}]{}%
Test \( x \MapsTo y \) test.

I feel the result is not tool bad. You may need to adjust the amount of vertical shift to suite the font in use. I've not scaled-down the \sim here, as it's not clear from the original question if it should be full-sized or small. It would be easy enough to do that, though, if necessary.

| improve this answer | |
  • 1
    (+1) How to adjust space when we want the symbol over the arrow? I tried with \xrightarrow{\raisebox{-0.25 em}{\smash{\ensuremath{\sim}}}} but doens't work. – Fabio Lucchini Jul 16 '18 at 8:26
  • @FabioLucchini Try \xrightarrow{\raisebox{-0.7ex}[0ex][0ex]{$\sim$}} (taken from here: tex.stackexchange.com/a/479324/35477) – Seub Dec 10 '19 at 12:01

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.