191

I am trying to put two subscripts at the left and right of a character. For example, something like: _{t} p_{x} where p is in the middle. How do you do this?

6
  • 2
    @Alan: Why a comment?
    – Caramdir
    Feb 20, 2011 at 1:40
  • @Caramdir It just seemed so short. I've added it as an answer.
    – Alan Munn
    Feb 20, 2011 at 1:51
  • 3
    Since this is essentially about left subscripts, you can also have a look at the answers to this question (possible duplicate). Feb 20, 2011 at 6:54
  • 6
    @Caramdir: The space has no effect in math mode ... Feb 20, 2011 at 6:57
  • 1
    @JPi: Done....... May 3, 2017 at 18:06

9 Answers 9

156

There are many tools for scripts:

  • For general math scripts before something, use \prescript provided by mathtools package, for better alignment:

    $ \prescript{14}{2}{\mathbf{C}} $

  • For large operators, use \sideset from amsmath:

    $ \sideset{_a^b}{'}\sum A_n $

  • For chemical equations, use mhchem package:

    \ce{^{227}_{90}Th+}

  • For tensors, use tensor package:

    $ M\indices{^a_b^{cd}_e} $
    $ \tensor[^a_b^c_d]{M}{^a_b^c_d} $

Please complete this list as you can.

The visual result: enter image description here

5
  • 23
    +1: I think that this is a great answer because it acknowledges the semantic element of LaTeX environments. Using tensor for, say, denoting an isotope is ontologically dodgy and its visual suitability is contingent on some hypothetical divergence of notation not occurring down the line. Feb 21, 2011 at 4:53
  • 1
    I tried most of these and found the \tensor solution the best one. Apr 29, 2014 at 12:20
  • Are there any options besides mhchem that don't require math mode? I'd like to typeset a downarrow before a letter in a phonetic transcription.
    – Sjiveru
    Jul 19, 2018 at 23:37
  • @RichardTerrett Worth mentioning that the difference is not just of semantic adherence: \sideset will only work with math operators, not with any item. Dec 11, 2019 at 20:15
  • Is there anything wrong (kerning?) with this simple approach? tex.stackexchange.com/a/317359/52160 Dec 12, 2019 at 7:39
71

Are you doing this in math mode?

${}_{t}p_{x}$

should work.

6
  • 1
    Spaces are ignored in math mode. $ _ t p _ x $ produces exactly the same effect.
    – TH.
    Feb 20, 2011 at 5:31
  • 35
    I would go for {}_{t}p_{x}, otherwise things like \sum _{t}p_{x} give surprising results. Feb 20, 2011 at 14:11
  • 3
    I think that the t and x are not aligned using this approach
    – becko
    Dec 2, 2013 at 22:22
  • 1
    @becko you'll need to match upper and lower i.e., ${}_{t} p_{x}$ and ${}_{t}^{} p_{x}^{n}$
    – Juhl
    Apr 13, 2015 at 12:22
  • 4
    This is the best answer as it uses plain Latex without any need for extra packages.
    – Andry
    Apr 4, 2019 at 20:42
24

The best solution I have seen so far was:

${}_{2}x_{1}$

pic1

For the more general case of left and right superscript and subscript, one writes:

${}^{1}_{2}x^{3}_{4}$

pic2

6
  • The question is about two subscript, one before and one after. It's not the same as having an upperscript and a subscript at the same place. Apr 22, 2016 at 7:42
  • 2
    just added how you can have both in the same place and compared to some other solutions here I think this is rater simple in syntax. Apr 22, 2016 at 7:46
  • As I said, you put a subscript and an upperscript and not two subscript Apr 22, 2016 at 7:48
  • ah ok I see your point Apr 22, 2016 at 7:50
  • Fixed that now. I did that because questions about left superscripts also get redirected to this post and marked as duplicates. Apr 22, 2016 at 7:56
22

The tensor package will do exactly what you require, and more. For your particular case, you need only type

\tensor[_t]{p}{_x}

Regards

22

You could use the leftidx package which is capable of producing left and right subscripts and superscripts.

In contrast to using simply consecutive subscripts or superscripts such as in $_{t}p_{x}$ it takes care of adjusting indices to the argument using \vphantom. From its source:

\newcommand\leftidx[3]{%
  {\vphantom{#2}}#1#2#3%
}
1
  • This is by far the best approach IMHO.
    – Al_Fh
    Sep 30, 2019 at 9:05
17

The amsmath package has a \sideset command which lets you put indices at all four corners of a symbol (even if this symbol itself has limits above/below):

\[  \sideset{_t}{_x}p  = \sideset{^*_*}{^*_*}\prod_*^*  \]

\sideset is intended to be used with large operator symbols such as \sum and \prod. The amsmath documentation says: this command is not designed to be applied to anything other than sum-class symbols. (Thanks to Stefan Kottwitz for this additional remark.) For other symbols, have a look at the other answers here.

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  • 12
    Good addition! Just a remark: \sideset is intended to be used with large operator symbols such as \sum and \prod. The amsmath documentation says: this command is not designed to be applied to anything other than sum-class symbols.
    – Stefan Kottwitz
    Feb 20, 2011 at 2:55
  • @Stefan: Ah, thanks ... I knew I should have looked it up before writing this. – So, don't use this with simple letter-symbols, use the other solutions given here. Feb 20, 2011 at 3:03
11

A simple method I apply - which does away with the need for extra packages - is the following:

~^o\!G_{Al}^i

Which produces the following: enter image description here

1
  • 2
    Welcome to TeX.SX! You can have a look at our starter guide to familiarize yourself further with our format. I think this solution is not ideal, because it will cause, at best, inconsistent spacing, or, at worst, a bad line break. Oct 25, 2014 at 13:56
6

I had the same problem with the subscript and superscript, sooo I made a package to make my life easier and to other. It's a common problem with actuarial symbol, and it help align the sub and superscript. Plus, I’ve add some shortcut to save time.

The project page and the CTAN.

All you need is the actuarialsymbol package.

At the beginning of the code you have to write

\usepackage{actuarialsymbol}

For the sub/superscript

\actsymb['subscripLeft']['superscriptL']{<middle>}{'subscriptR'}{'superscriptR'}

Example of output:

enter image description here

Example of shortcut for actuarial symbol : enter image description here

5
  • 1
    Welcome to LaTeX! Is this meant as an answer for another question?
    – Moriambar
    Apr 26, 2017 at 20:27
  • 1
    Congratulations! Nice package!
    – Zarko
    Apr 26, 2017 at 20:33
  • 1
    @Moriambar it is: tex.stackexchange.com/a/366883 ;)
    – cgnieder
    Apr 26, 2017 at 20:35
  • @clemens My package can fulfill many problems. Jul 31, 2018 at 18:22
  • @Zarko thanks! If you have idea of upgrade we are open for it. We are working on a mathjax upgrade for ebook. Jul 31, 2018 at 18:23
6

I am dissatisfied with the existing options, including \prescript from mathtools, since they do not even make an attempt at fixing the spacing between the symbol and the left superscript. Therefore, based on egreg’s excellent answer here, I recently added the package leftindex to CTAN. It provides the command

\leftindex^{<left superscript>}_{<left subscript>} {<symbol>}

This measures the negative indentation of the right subscript and indents the left superscript by the same value. This works well for most symbols, with a few exceptions, such as A and L (and P and \Gamma in some fonts other than Computer Modern). Therefore, \leftindex takes a couple of optional arguments. The only one we shall need right now is

\leftindex[<slanting phantom>]^{<left superscript>}
    _{<left subscript>} {<symbol>}

If the command receives a <slanting phantom>, it will use this symbol instead of <symbol> to calculate the indentation of the left superscript.

\documentclass{article}

\usepackage{leftindex}

\begin{document}

Good results:
$
    \leftindex^a_b {f}, \leftindex^* {M}, \leftindex_q^p {H},
    \displaystyle
    \leftindex_{-\infty}^{\infty} {\int} f(x)\, dx
$

Bad results:
$
    \leftindex^* {A}, \leftindex^a_b {L}
$

With slanting correction:
$
    \leftindex[T]^* {A}, \leftindex[I]^a_b {L}
$

\end{document}

enter image description here


If you grow tired of having to write slanting phantoms manually, you can have a look at my other package, SemanTeX, which provides semantic, keyval-based mathematics where notation can be controlled centrally from the preamble. Its left index support is based on leftindex, but slanting phantoms can now be chosen once and for all from the preamble:

\documentclass{article}

\usepackage{semantex}

\NewVariableClass\MyVar[output=\MyVar]

% No slanting phantom needed:

\NewObject\MyVar\vf{f}

\NewObject\MyVar\vM{M}

\NewObject\MyVar\vH{H}

% Slanting phantom needed:

\NewObject\MyVar\vL{L}[slanting phantom=I]

\NewObject\MyVar\vGamma{\Gamma}[slanting phantom=]

% Slanting phantom and a \!\! to the
% right of the superscript needed:

\NewObject\MyVar\vA{A}[
    slanting phantom=I,
    post upper left=\!\!,
]

\begin{document}

$ \vf[upper left=a,lower left=b] $,
$ \vM[upper left=*] $,
$ \vH[upper left=p,lower left=q] $,

$ \vA[upper left=*] $,
$ \vL[upper left=a,lower left=b] $

\end{document}

enter image description here

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