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I want to fine-tune the placement of subscripts and superscripts next to large parentheses. Since the large parentheses bulge out, they push the sub/superscripts too far to the right. MWE:

\documentclass{article}

\begin{document}
\[ \left(\frac{1}{2}A + B\right)_2 \]
\end{document}

Large parentheses push subscript too far to the right

Is there a way to fine-tune this? Just to nudge the 2 over a bit? I'm using pdfTeX, Version 3.1415926-2.5-1.40.14 (TeX Live 2013/Debian)

David M.
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    Welcome to TeX.SX! Just avoid \left and \right. They add nothing and actually do harm. If you really need larger parentheses, for this case use \bigl( and \bigr). – egreg Mar 20 '17 at 23:49
  • Although in this case larger parentheses are not indicated. I mean as a matter of taste you're free to do whatever you like, but there is no need of large parentheses here, you're creating a problem you don't need. If you really want a visual contrast to the brackets around the arguments of the function, why not consider using square brackets? – Au101 Mar 20 '17 at 23:53
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    Toatally agree that such large parenthesis in this case are not needed. But, to nudge the subscripts, you can apply a negative thin space: So instead of _2 use _{\!2} or _{\!\!2}. Also, while code snippets are useful in explanations, it is always best to compose a fully compilable MWE that illustrates the problem including the \documentclass and the appropriate packages so that those trying to help don't have to recreate it. – Peter Grill Mar 21 '17 at 00:11
  • Anyway, I don't get those humongous parentheses with your code in a standard document. Please, make a real example. – egreg Mar 21 '17 at 08:23
  • @egreg Updated to include MWE, thanks. Why are \left and \ right bad? – David M. Mar 21 '17 at 17:51
  • @DavidM. Not in this case, of course. But it's normal that, when the parenthesis becomes very large, you need \! to nudge the subscript or superscript. I always do it. – egreg Mar 21 '17 at 17:59
  • @DavidM. - For discussions of why it can be suboptimal to use \left and \right see, e.g., Is it ever bad to use \left and \right? and “(” or “\left(” parentheses? – Mico Mar 21 '17 at 18:20

1 Answers1

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You could "nudge" the subscript to the left, i.e., place it closer to the closing parenthesis, by writing _{\!\!2} (two negative thinspaces) or _{\!2} (one negative thinspace) instead of just _2. Even better, though, would be not to use \left and \right to auto-size the parentheses to begin with. In fact, \left and \right may be the root cause of the problem, since the parentheses that are produced by \left( and \right) are needlessly large. Consider the following screenshot:

enter image description here

The first row is produced by your code, i.e., by \left(\frac{1}{2}A + B\right)_2. The second row shows the effect of nudging the subscript to the left via _{\!\!2}. In the third row, \Bigl and \Bigr are used instead of \left and \right; here, much less "nudging" is required.

The final row uses \tfrac ("text style \frac") to create a smaller, but still perfectly readable fraction term along with \bigl and \bigr. Now, no nudging is required at all. I would argue that the expression in the final row is the most readable of the four. :-)

\documentclass{article}
\usepackage{amsmath} % for 'gather*' environment
\begin{document}
\begin{gather*}
  \left(\frac{1}{2}A + B\right)_2 \\
  \left(\frac{1}{2}A + B\right)_{\!\!2}\\
  \Bigl(\frac{1}{2}A+B\Bigr)_{\!2}\\
  \bigl(\tfrac{1}{2}A+B\bigr)_2
\end{gather*}
\end{document}
Mico
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