# Should superscripts be carried out of a fraction?

I can't help stumbling upon the usual way LaTeX renders fractions with superscripts:

I think that the asterisk has a lower "weight" then the symbol and should not be treated as equal. I find something in line with

to be aesthetically more pleasing. Are there any guidelines on the matter? If the above is indeed better, what are the technical means to achieve this?

• From an aesthetically point of view, I would rather use \sfrac{}{} from the xfrac package -- it will display the fraction in the a/b style
– user31729
Nov 2, 2014 at 7:32
• @ChristianHupfer Though I liked the alternative of using split level fractions, it turns out that it is subjected to the same flaw sfrac{\beta^*}{\beta} leaves to much space for the asterisk, even sfrac{\beta^*\!}{\beta} still seems to be a bit sparse. Nov 2, 2014 at 8:11

To prevent the symbols from becoming so small as to be virtually unreadable, I would not use a \frac expression for the superscript material. Instead, I would use "inline" style:

$a^{\beta^*/\beta}$


This approach can be used for both display-style and inline-style occurrences. The only difference will be that the exponent will be typeset at normal height when in displaystyle math mode, but in "cramped" mode (i.e., at a slightly lower height) when in textstyle math mode. Feel free to place round parentheses around the expression in the exponent if you think that this enhances readability.

\documentclass{article}
$a^{\beta^*\!\!/\!\beta} \v a^{(\beta^*\!\!/\!\beta)} \v a^\frac{\beta^*}{\beta} \v a^{\frac{\beta}{\beta}^{\!*}}$
$\displaystyle a^{\beta^*\!\!/\!\beta} \v a^{(\beta^*\!\!/\!\beta)} \v a^\frac{\beta^*}{\beta} \v a^{\frac{\beta}{\beta}^{\!*}}$

The first form is certainly clearer mathematically, if superscripts such as ^{*} or ^{2} were automatically lifted out of the fraction how would you distinguish \frac{a^{2}}{b}} from \frac{a}{b}^{2}. If there is a context where the meaning is clear the author always has the option of marking it up in the second form (or hiding the width of the superscript in other ways) but it certainly shouldn't be the default.
• I think one should use something like \left(\frac{a}{b}\right)^{2} instead of \frac{a}{b}^{2}.