def mynumerator(x): if parent(x) == R: return x return numerator(x) class fastfrac: def __init__(self,top,bot=1): if parent(top) == ZZ or parent(top) == R: self.top = R(top) self.bot = R(bot) elif top.__class__ == fastfrac: self.top = top.top self.bot = top.bot * bot else: self.top = R(numerator(top)) self.bot = R(denominator(top)) * bot def reduce(self): return fastfrac(self.top / self.bot) def sreduce(self): return fastfrac(I.reduce(self.top),I.reduce(self.bot)) def iszero(self): return self.top in I and not (self.bot in I) def isdoublingzero(self): return self.top in J and not (self.bot in J) def __add__(self,other): if parent(other) == ZZ: return fastfrac(self.top + self.bot * other,self.bot) if other.__class__ == fastfrac: return fastfrac(self.top * other.bot + self.bot * other.top,self.bot * other.bot) return NotImplemented def __sub__(self,other): if parent(other) == ZZ: return fastfrac(self.top - self.bot * other,self.bot) if other.__class__ == fastfrac: return fastfrac(self.top * other.bot - self.bot * other.top,self.bot * other.bot) return NotImplemented def __neg__(self): return fastfrac(-self.top,self.bot) def __mul__(self,other): if parent(other) == ZZ: return fastfrac(self.top * other,self.bot) if other.__class__ == fastfrac: return fastfrac(self.top * other.top,self.bot * other.bot) return NotImplemented def __rmul__(self,other): return self.__mul__(other) def __div__(self,other): if parent(other) == ZZ: return fastfrac(self.top,self.bot * other) if other.__class__ == fastfrac: return fastfrac(self.top * other.bot,self.bot * other.top) return NotImplemented def __pow__(self,other): if parent(other) == ZZ: return fastfrac(self.top ^ other,self.bot ^ other) return NotImplemented def isidentity(x): return x.iszero() def isdoublingidentity(x): return x.isdoublingzero() R. = PolynomialRing(QQ,8,order='invlex') I = R.ideal([ mynumerator((ua*ux1^2+uy1^2)-(1+ud*ux1^2*uy1^2)) , mynumerator((ux1)-(uZ1/uX1)) , mynumerator((uy1)-(uZ1/uY1)) , mynumerator((ud2)-(2*ud)) ]) ua = fastfrac(ua) ud2 = fastfrac(ud2) ud = fastfrac(ud) ux1 = fastfrac(ux1) uy1 = fastfrac(uy1) uX1 = fastfrac(uX1) uY1 = fastfrac(uY1) uZ1 = fastfrac(uZ1) uA = ((uX1^2)) uB = ((uY1^2)) uU = ((ua*uB)) uC = ((uA+uU)) uD = ((uA-uU)) uE = (((uX1+uY1)^2-uA-uB)) uX3 = ((uC*uD)) uY3 = ((uE*(uC-ud2*uZ1^2))) uZ3 = ((uD*uE)) ux3 = (((ux1*uy1+uy1*ux1)/(fastfrac(1)+ud*ux1*ux1*uy1*uy1))).reduce() uy3 = (((uy1*uy1-ua*ux1*ux1)/(fastfrac(1)-ud*ux1*ux1*uy1*uy1))).reduce() print isidentity((ua*ux3^2+uy3^2)-(fastfrac(1)+ud*ux3^2*uy3^2)) print isidentity((ux3)-(uZ3/uX3)) print isidentity((uy3)-(uZ3/uY3))