How to put a symbol above another in LaTeX?

Question

How to put a symbol above (on the head of) another? For example, I want to produce something like this in one line.

a
#

i.e., a above #.

The effect should be almost the same with $#^a$ except that a is on the top instead of top right of #.

Do you want them both to be the same size? And how should they appear in relation to the surrounding text? Should the # be in line with the text, or should the midpoint between a and # be in line with it? — Artelius, Jun 23 '10 at 03:12
Thanks for the quick reply Artelius. About their size, the above one is smaller would be preferred. The effect should be the same as $#^a$ except that 'a' is on the top of '#' other than on the top right of '#'. — day, Jun 23 '10 at 03:26
This was closed as off topic. I think it should be migrated to TeX.se. It may not be able to, because it's too old. At the time of its posting it was accepted that LaTeX was a programming language and that such questions were welcome here. — Geoff, Dec 04 '13 at 13:51

score 116 · Accepted Answer · answered Jun 23 '10 at 03:43

116

Use \overset{above}{main} in math mode. In your case, \overset{a}{\#}.

answered Jun 23 '10 at 03:43

Artelius

score 25 · Answer 2 · answered Jun 23 '10 at 08:45

25

${a \atop \#}$

or

${a \above 0pt \#}$

answered Jun 23 '10 at 08:45

Alexey Malistov

1

Alexey, LaTeX complains the two commands are foreign. Also, the two symbols are put equal size which is not what I wanted. Artelius's answer matches my needs perfectly. Anyway, thank you all the same. – day Jun 26 '10 at 06:58

score 25 · Answer 3 · edited Jul 30 '19 at 21:10

25

If you're using # as an operator, consider defining a new operator for it:

\newcommand{\pound}{\operatornamewithlimits{\#}}

You can then write things like \pound_{n = 1}^N and get:

edited Jul 30 '19 at 21:10

Glorfindel

answered Jun 24 '10 at 21:27

Geoff

3 Answers3