@skirpichev It wont affect the solutions of any other equations and also correct the issue because I have used ```.could_extract_minus_sign``` to detect the sign in constantsimp so that cancellation of terms should not take place (explained in description above) and similarly I will use ```.could_extract_minus_sign``` in constant_renumber so as to undo the negative sign put in constantsimp.
For example, taking the issue example only
solution numerator is ```(x**2 + exp(2*C1))``` and its denominator is ```(x**2 - exp(2*C1))``` after applying constantsimp by my method will convert it with num being ```C1 + x**2``` and denum being ```-C1 + x**2``` and after constant_renumber its num will be ```C2 + x**2``` and denum will be ```-C1 + x**2```.
If I add a condition at the end of constant_renumber to check the sign of constant and change it if negative then sol denum will become ```C1 + x**2```.
And using this the test cases answer which you pointed out will become as earlier it was.

Please provide feedback, is it ok?