Normal form for rational fractions : ratnormal

ratnormal rewrites an expression using it's irreductible representation. The expression is viewed as a multivariate rational fraction with coefficients in $\mathbb {Q}$ (or $\mathbb {Q}$[i]). The variables are generalized identifiers which are assumed to be algebraically independant. Unlike with normal, an algebraic extension is considered as a generalized identifier. Therefore ratnormal is faster but might miss some simplifications if the expression contains radicals or algebraically dependant transcendental functions.
Input :

ratnormal((x^3-1)/(x^2-1))

Output :

(x^2+x+1)/(x+1)

Input :

ratnormal((-2x^3+3x^2+5x-6)/(x^2-2x+1))

Output :

(-2*x^2+x+6)/(x-1)