# Aesthetic issue in fractions

While I was typing a document related to special relativity, I came across this slight misalignment in \frac{V}{c}(shown with huge text size so that the effect is easily seen)

The 'problem' is that the V's bottom point is not at all close to c's top point. I'm guessing that this has something to do with the fact that the alignment is done using the borders of bounding boxes and that due to V's asymmetric design (perhaps exaggerated by the relative thickness of its slant edges?).

On trying \frac{\mathrm{V}}{\mathrm{c}}, one obtains:

This looks good by itself but extremely out of place with all the other variables italicised in the equation. I would not like to use mathrm everywhere as entire non-italicised equations are somewhat harder to read in my opinion. Also, speed of light is always written as c and not c.

My question : is there any 'middle-way' solution to this (using alternate fonts or otherwise)? An ideal solution would be to very slightly 'straighten' V and c to get a cross between the two illustrated cases.

On another note: is this even a problem? While I certainly noticed it at normal font size, I'm not sure whether this is something to be taken seriously or not.

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Does this (tex.stackexchange.com/questions/84243/…) help? –  Masroor Feb 13 at 5:23
@MMA the hfill solution doesn't work as it shifts c way too much to the left. –  varun Feb 13 at 7:30
I don't think the fraction would be better if the vertex of the V is aligned with the top point of c. Rather, I'm convinced of the contrary. –  egreg Feb 13 at 10:46
@egreg , I am not saying that the vertex of V ought to be aligned with the top point of c but I am looking for a middle-way between the two pictures posted above. However, I do think that this large gap presented first is alarming; it ought to be small but not zero, imho. –  varun Feb 14 at 11:15

If centering bottom of V over mid top of C is the concern, you can push V to right. I agree with Mico and Barbara in the values of space and adjusted it accordingly

\documentclass{article}
\usepackage{mathtools}
\mathtoolsset{mathic=true}
\newcommand\VV{\mkern3mu V}
\begin{document}
$\frac{\VV}{c\,}$
\end{document}


For re-usability, I have introduced a macro. You can adjust the amout of push to suit your needs.

Another method to fix the fraction line is to fix the width of numerator with a box.

\documentclass{article}
\usepackage{mathtools}
\mathtoolsset{mathic=true}
\newcommand\VV{\makebox[\widthof{$\mathrm{V}$}]{$\mkern6mu V$}}
\begin{document}
$\frac{\VV}{c}$
\end{document}


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Positioning the italic-V such that its bottom is centered over the top of the italic-c character may be too much of a good thing, as doing so produces a lot of "dead space" at the left-hand end of the fraction bar. A more subtle adjustment, say \mkern 2mu or \mkern 3mu, may be all that's needed to achieve optical balance of the numerator and denominator terms. –  Mico Feb 13 at 6:05
i think it might be better to shove the c a bit to the left, maybe by adding a thin or thick space after it. (true, it won't be centered, but which is better, an off-center c or an over-long fraction rule with an "empty" left end?) –  barbara beeton Feb 13 at 13:57
@barbarabeeton I agree and corrected. Thanks :) –  Harish Kumar Feb 13 at 14:08
The first solution works like a charm. Thanks. :) –  varun Feb 14 at 11:08

You can achieve the result without losing symmetry of the underline by using a stack. In particular, \def\useanchorwidth{T} setting says to use the width of the first argument (the anchor) in defining the width of the stack. Thus, shifting around the horizontal location of the 2nd argument doesn't affect the underline.

\documentclass{article}
\usepackage{stackengine}
\def\VV{%
\renewcommand\useanchorwidth{T}%
\setstackgap{L}{0pt}%
\renewcommand\stacktype{L}%
\stackon{\,\phantom{V}\,}{\;V}%
}
\stackMath
\begin{document}
$\frac{\VV}{c}$
\end{document}


\documentclass{article}
\usepackage{stackengine}
\def\VV{%
\renewcommand\useanchorwidth{T}%
\setstackgap{L}{0pt}%
\renewcommand\stacktype{L}%
\stackon{\phantom{V}}{\;V}%
}
\stackMath
\begin{document}
$\frac{\VV}{c}$
\end{document}


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