Thanks; I've now used patch-2.0.12u3 successfully; the trouble was
simply that in the doc directory I had a single file docr1.dvi and
had thrown away the tex files for the individual chapters. As I'm
using gapexe.next, I told patch to skip the changes on the source
code.

Is the source code for gapexe.next available ? It would seem that
to patch the source, one would need to do apply the upgrades to the
source code src3r1 and then make whatever changes were made in order
to produce the source code for gapexe.next, and then recompile. (Wish
I'd thought of that earlier :). Perhaps the simplest thing is to wait
for Gap 3.2 ?

Geoff Mess