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((uy1^2)-(ux1^3+ua*ux1^2+16*ua*ux1)) , mynumerator((ux1)-(uX1/uZ1)) , mynumerator((uy1)-(uY1/uZZ1)) , mynumerator((uZZ1)-(uZ1^2)) , mynumerator((ua4)-(4*ua)) ]) ua4 = fastfrac(ua4) ua = fastfrac(ua) ux1 = fastfrac(ux1) uy1 = fastfrac(uy1) uX1 = fastfrac(uX1) uZZ1 = fastfrac(uZZ1) uY1 = fastfrac(uY1) uZ1 = fastfrac(uZ1) uA = ((uX1^2)) uU = ((ua4*uZZ1)) uB = ((uA-fastfrac(4)*uU)) uC = ((uA*uU)) uZ3 = (((fastfrac(2)*uY1)^2)) uX3 = ((uB^2)) uY3 = ((uY1*uB*(fastfrac(2)*(uX3+fastfrac(32)*uC)+ua*(uZ3-uC)))) uZZ3 = ((uZ3^2)) ux3 = ((fastfrac(1)/(fastfrac(4)*uy1^2)*ux1^4-fastfrac(8)*ua/uy1^2*ux1^2+fastfrac(64)*ua^2/uy1^2)).reduce() uy3 = ((fastfrac(1)/(fastfrac(8)*uy1^3)*ux1^6+((-ua^2+fastfrac(40)*ua)/(fastfrac(4)*uy1^3))*ux1^4+((ua*uy1^2+(fastfrac(16)*ua^3-fastfrac(640)*ua^2))/(fastfrac(4)*uy1^3))*ux1^2+((-fastfrac(4)*ua^2*uy1^2-fastfrac(512)*ua^3)/uy1^3))).reduce() print isidentity((uy3^2)-(ux3^3+ua*ux3^2+fastfrac(16)*ua*ux3)) print isidentity((ux3)-(uX3/uZ3)) print isidentity((uy3)-(uY3/uZZ3)) print isidentity((uZZ3)-(uZ3^2))