Excessive white space after exponents

[5nizza]

Brief outline of the bug

There is an excessive white space after exponents.
Please see the picture explanation.

Minimal example showing the bug

\RequirePackage{latexbug}
\documentclass{article}

\begin{document}

The problem can be solved in $2^{2^{O(n)}}$ time.

The problem can be solved in $2^{2^{O(n)}}\!$ time.

\vspace{4mm}

Consider the state $(q^S,v,t)$.

Consider the state $(q^S\!,v,t)$.

\end{document}

Log file (required) and possibly PDF file

bad_white_space.log

[davidcarlisle]

This is not under the control of LaTeX. It is a primitive TeX feature that additional space is added. this is the user settable length \scriptspace which you can set to 0pt if you do not wish it to be added.

\documentclass{article}

\begin{document}

The problem can be solved in $2^{2^{O(n)}}$ time.

\setlength\scriptspace{0pt}
The problem can be solved in $2^{2^{O(n)}}$ time.

The problem can be solved in $2^{2^{O(n)}}\!$ time.

\vspace{4mm}

Consider the state $(q^S,v,t)$.

Consider the state $(q^S\!,v,t)$.

\end{document}