The size of an integer is assumed to be at least 4 Bytes long.

The overstrike line is positioned at the mean height
of every block of text not broken by vertical movements and font
changes.

The current state of change bar mode and overstrike mode
must be committed do environments, which are placed on different
locations than the current text. This is done by redefining
\color@begingroup and \color@endgroup.
