I have lost the thread, but the other day there were a few messages
about the "simplification" x / x --> 1. Setting gcd to false
prevents Maxima from cancelling common factors in some, but not
all expressions. For example:
(%i1) ratsimp(x/(x^2 + x)), gcd : false;
(%o1) x/(x^2+x)
(%i2) ratsimp(x/(x^2 + x)), gcd : subres;
(%o2) 1/(x+1)
(%i3) x/x, gcd : false;
(%o3) 1
Setting gcd to false isn't enough to keep Maxima from simplifying
x / x --> 1. Unfortunately, x / x doesn't get sent to pgcda (in
rat3c.lisp).
So setting gcd to false doesn't inhibit the simplification x / x --> 1.
Barton