Dear Forum,

I have put a small patch onto our ftp server:

ftp://ftp.math.rwth-aachen.de/pub/incoming/xgap-playback-patch

This patch will add two new functions to XGAP 1.3 (the version
distributed with GAP 3.4.4) which you might find useful if you are
giving a demonstration of programs in GAP, namely:

`Playback( <file> )'
`ResumePlackback()'

After `Playback' has been executed, 'XGAP' will wait for a keystroke.
If you press any key except 'q' and 'z' then the next line from
<file> will be read in as if you have typed it. Pressing 'q' will
suspend the playback mode until you execute a 'ResumePlayback',
pressing 'z' will cancel the playback mode completely.

The difference to 'Read' is, that it looks like you are typing the
commands (so there is a GAP prompt, commands appear on the command
line, the result is printed) *and* you have full control when the
next command is executed. So you can type ' ', explain the command
and its output, and then move on to the next command with just a
single keystroke.

In order to apply the patch go into the directory containing xgap and
do a "patch -p3 < xgap-playback-patch". Note that I have not tested
the addition thoroughly, so it might not compile or cause XGAP to crash
(I do not hope so, but - as I said - it is not really tested).

I hope that this is of some use, best wishes
Frank