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When it is requested to write letter "í" in math mode, it happens that $\acute{i}$ is not the right answer as it could be expected: the accent (´) is written over the letter (i), without deleting/overwriting the upper dot (^{.}) Another possiblity to solve the problem: $\acute{\imath}$, not always works satisfactorily. Is there another way to do it, obtaining an acceptable/appropriate character?

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  • While I don’t recommend it, \mathalpha{\textit{\acute{i}}} is another way.
    – Davislor
    Feb 20, 2021 at 22:38

1 Answer 1

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$\acute{\imath}$ is the right way. What do you mean by "not always works satisfactorily"?

In general, \imath and its companion \jmath should be used for the math accents:

  • \acute{\imath}
  • \grave{\imath}
  • \dot{\imath} (ambiguous!)
  • \ddot{\imath}

and so on.

\documentclass{article}

\usepackage{inputenc}
\usepackage{amsmath} % tex.stackexchange.com/questions/69373/#comment148505_69374

\begin{document}
  $\imath$ $\acute{\imath}$ $\acute{i}$ $\grave{\imath}$ $\dot{\imath}$ $i$ $\ddot{\imath}$
  
  $\jmath$ $\acute{\jmath}$ $\acute{j}$ $\grave{\jmath}$ $\dot{\jmath}$ $j$ $\ddot{\jmath}$
  
  $X_{\mathrm{s\acute\imath}}$ $X_{\textup{s\'i}}$ $X_{\textup{sí}}$
\end{document}

enter image description here

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  • What is the difference between your suggestion and those one wrote on the question?
    – Sigur
    Aug 30, 2012 at 1:00
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    Well, what I want to say is the next: when you have the expression $X_{\rm s\acute\imath}$, the grammar is more or less ok, but not completely correct, because the second letter is not in \rm. Is it feasible to write completly the subscript in normal text (e.g. roman)?
    – user17133
    Aug 30, 2012 at 3:13
  • @paritto If you need a textual subscript, use $X_{\textup{s`i}}$ or $X_{\textup{sì}}$ (if you are using inputenc); this needs the amsmath package.
    – egreg
    Aug 30, 2012 at 9:44
  • @egrep: Just \text as I know. When using \textup, amsmath is not needed.
    – Leo Liu
    Aug 30, 2012 at 9:50
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    @LeoLiu With amsmath, \textup will take care of the size in a subscript; without the package it wouldn't. With \text the current font will be used, with \textup the upright shape will certainly be selected.
    – egreg
    Aug 31, 2012 at 9:34

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