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,10,order='invlex') I = R.ideal([ mynumerator((uy1^2)-(ux1^4+2*ua*ux1^2+1)) , mynumerator((ux1)-(uX1/uZ1)) , mynumerator((uy1)-(uY1/uZZ1)) , mynumerator((uXX1)-(uX1^2)) , mynumerator((uZZ1)-(uZ1^2)) , mynumerator((uR1)-(2*uX1*uZ1)) , mynumerator((ua^2+uc^2)-(1)) ]) ua = fastfrac(ua) uc = fastfrac(uc) ux1 = fastfrac(ux1) uy1 = fastfrac(uy1) uR1 = fastfrac(uR1) uXX1 = fastfrac(uXX1) uX1 = fastfrac(uX1) uZZ1 = fastfrac(uZZ1) uY1 = fastfrac(uY1) uZ1 = fastfrac(uZ1) uA = ((uXX1^2)) uB = ((uZZ1^2)) uC = ((uA+uB)) uD = ((fastfrac(2)*((uXX1+uZZ1)^2-uC))) uE = ((uA-uB)) uF = ((fastfrac(2)*uA)) uG = ((fastfrac(2)*uB)) uJ = ((ua*uD+fastfrac(2)*uC)) uK = ((uJ+uE)) uL = ((uJ-uE)) uM = ((uC*uE)) uN = ((uG*uK)) uP = ((uF*uL)) uX3 = ((uX1*(uM-uN))) uY3 = ((uY1*((uM+uN)*(uP-uM)+(uD*uE)^2))) uZ3 = ((uZ1*(uP+uM))) uXX3 = ((uX3^2)) uZZ3 = ((uZ3^2)) uR3 = (((uX3+uZ3)^2-uXX3-uZZ3)) ux2 = (((ux1*uy1+uy1*ux1)/(fastfrac(1)-(ux1*ux1)^2))).reduce() uy2 = ((((fastfrac(1)+(ux1*ux1)^2)*(uy1*uy1+fastfrac(2)*ua*ux1*ux1)+fastfrac(2)*ux1*ux1*(ux1^2+ux1^2))/(fastfrac(1)-(ux1*ux1)^2)^2)).reduce() ux3 = (((ux1*uy2+uy1*ux2)/(fastfrac(1)-(ux1*ux2)^2))).reduce() uy3 = ((((fastfrac(1)+(ux1*ux2)^2)*(uy1*uy2+fastfrac(2)*ua*ux1*ux2)+fastfrac(2)*ux1*ux2*(ux1^2+ux2^2))/(fastfrac(1)-(ux1*ux2)^2)^2)).reduce() print isidentity((uy3^2)-(ux3^4+fastfrac(2)*ua*ux3^2+fastfrac(1))) print isidentity((ux3)-(uX3/uZ3)) print isidentity((uy3)-(uY3/uZZ3)) print isidentity((uXX3)-(uX3^2)) print isidentity((uZZ3)-(uZ3^2)) print isidentity((uR3)-(fastfrac(2)*uX3*uZ3))