> Obviously, another approach for easy examples like this is something like
> (%i1) e : a.b.c$
> (%i2) subst(c^^(-1), b, e);
> (%o2) a
> I actually use this idea quite a lot (for commutative expressions) when
> I don't want ratsubst to mess up the structure of the expression.
> Rupert
That's cute--never would have thought of that---I was aiming for an ad-hoc method, not some grand general scheme
(but I think ratsubst should be able to handle the some easy cases). Thanks,
Barton