rendering brackets

[David Carlisle]

One last attempt to explain this

> Let's look at the other styles, as you can see from the attachment,
> both '1' and 'a' are first placed in boxes of the same height.

No, they are not boxed.

> Both the height of the individual characters and the sum of the heights of the
> is then of no importance.

No the height of 1 and a affect all these,


> All the different styles produce fractions of the same height and
> are rendered with the same brackets,
>  except the one rendered in displaystyle.

The brackets are available in discrete sizes so there are edge effects
when the size changes: it's not always obvious when a slightly larger
expression will get the next available size.

at normal size it happens that all but one of the pairs give the same
size brackets, but try for example Huge and all the pairs have 1/a
bigger than a/1 except scriptscriptsize where they are the same.

I don't have a stdbook package but it didn't seem needed.

I removed the \\ as they were generating warnings not related to the issue.


%
%    2018061700 - M.J. Baars (mjbaars1977 at gmail.com)
%

\documentclass[10pt,twoside,a4paper]{book}

\usepackage{amsfonts}
\usepackage{amsmath}
\usepackage{amssymb}

\usepackage{graphicx}
%\usepackage{stdbook}
\parskip=\bigskipamount

\begin{document}
\Huge

    normal:            \scalebox{2}{${                \left(
\frac{1}{a} \right)}$}
                \scalebox{2}{${                \left( \frac{a}{1} \right)}$}

    displaystyle:        \scalebox{2}{${\displaystyle        \left(
\frac{1}{a} \right)}$}
                \scalebox{2}{${\displaystyle        \left( \frac{a}{1}
\right)}$}

    scriptstyle:        \scalebox{2}{${\scriptstyle        \left(
\frac{1}{a} \right)}$}
                \scalebox{2}{${\scriptstyle        \left( \frac{a}{1} \right)}$}

    scriptscriptstyle:    \scalebox{2}{${\scriptscriptstyle    \left(
\frac{1}{a} \right)}$}
                \scalebox{2}{${\scriptscriptstyle    \left(
\frac{a}{1} \right)}$}

    textstyle:        \scalebox{2}{${\textstyle        \left(
\frac{1}{a} \right)}$}
        \scalebox{2}{${\textstyle        \left( \frac{a}{1} \right)}$}

\end{document}


David