LogInputTo( filename )
LogInputTo causes the subsequent input lines to be logged to the
file with the name filename, i.e., every line you type will also
appear in this file. This file must of course be writable by GAP,
otherwise an error is signalled. Note that LogInputTo will
overwrite the previous contents of this file if it already existed.
LogInputTo()
In this form LogInputTo stops logging again.