Several years ago I did some symbolic algebra manipulations that ended up being very helpful. I did this on an Ubuntu machine (ubuntu 16) running Sage 7.4

Recently I installed the newest version of Sage 8.9, and reran some of my older notebooks. The 'simplify' function no longer produces the same output, and makes the rest of my calculations fail.

Is there something I am missing? Or has the algorithm changed?

simplify_full() on this equation:

(Z*a + Z*w2 - a + w2)*(Z*a + Z*w3 - a + w3)*y == (Z*a + Z*w1 - a + w1)*G*(Z + 1)*x

used to produce the following output:

(a^2 + a*w2 + (a+w2) *w3)*Z*2*y − 2*(a^2 − w2*w3)*Z*y + (a^2 − a*w2 − (a − w2)*w3)*y == G*Z^2*(a + w1)*x + 2*G*Z*w1*x − G*(a − w1)*x

It now produces this output:

((Z^2 - 2*Z + 1)*a^2 + (Z^2 - 1)*a*w2 + ((Z^2 - 1)*a + (Z^2 + 2*Z + 1)*w2)*w3)*y == ((G*Z^2 - G)*a + (G*Z^2 + 2*G*Z + G)*w1)*x

Is there anything I can do to force the original output using Sage 8.9 and a Jupyter Notebook?