Compare symbolic expressions

edit

Following is the problem I am trying to solve:

I have multiple complex symbolic expressions f1(x1,x2,...,xn),f2(x1,x2,...,xn),...,fn(x1,x2,...,xn) which are functions of symbolic variables x1,x2,...,xn. I also have some constraints for the symbolic variables, e.g. 0 is smaller than x1, 2 is smaller than x2, x2 is integer, etc. How can I find out for two selected symbolic expressions which one is larger for given constraints?

I've tried something like:

assume(0<x1,2<x2)< p="">

assume(x2,'integer')

bool(f1>f2)

It seems to work for more simple symbolic expressions. For more complex symbolic expressions (where a solution definitely exists) SAGE seems not to be able to compare the expressions. Is there a way to overcome this?