Hi, I want to compare (or test the equality of) two ex objects which contain symbols. a = a0 + x*a1; b = a0 + a1*x; If the ex objects are evaluated (symbolically), such that a-b becomes 0, then the test would be finished. However, how do I evaluate such a expression as a-b symbolically? Or are there other ways of comparing two such ex objects? Any suggestions on how to do this? Thanks, Vera Louise Hauge