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*ux1^3+uy1^3+1)-(ud*ux1*uy1)) , mynumerator((ux1)-(uX1/uZ1)) , mynumerator((uy1)-(uY1/uZ1)) , mynumerator((ud*urecipd)-(1)) ]) urecipd = fastfrac(urecipd) ua = fastfrac(ua) ud = fastfrac(ud) ux1 = fastfrac(ux1) uy1 = fastfrac(uy1) uX1 = fastfrac(uX1) uY1 = fastfrac(uY1) uZ1 = fastfrac(uZ1) uU = ((ua*uX1*uX1^2)) uV = ((uY1*uY1^2)) uW = ((uZ1*uZ1^2)) uA = (((uU-uV)^2)) uB = (((uU-uW)^2)) uC = (((uV-uW)^2)) uD = ((uA+uC)) uE = ((uA+uB)) uX3 = ((urecipd*(uU+uV+uW)*(uB+uD))) uY3 = ((fastfrac(2)*uU*uC-uV*(uC-uE))) uZ3 = ((fastfrac(2)*uV*uB-uU*(uB-uD))) ux2 = (((ux1-uy1^3*ux1)/(ua*uy1*ux1^3-uy1))).reduce() uy2 = (((uy1^3-ua*ux1^3)/(ua*uy1*ux1^3-uy1))).reduce() ux3 = (((ux1-uy1^2*ux2*uy2)/(ua*ux1*uy1*ux2^2-uy2))).reduce() uy3 = (((uy1*uy2^2-ua*ux1^2*ux2)/(ua*ux1*uy1*ux2^2-uy2))).reduce() print isidentity((ua*ux3^3+uy3^3+fastfrac(1))-(ud*ux3*uy3)) print isidentity((ux3)-(uX3/uZ3)) print isidentity((uy3)-(uY3/uZ3))