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(GF(2),6,order='invlex') I = R.ideal([ mynumerator((ux1^3+uy1^3+1)-(3*ud*ux1*uy1)) , mynumerator((ux1)-(uX1/uZ1)) , mynumerator((uy1)-(uY1/uZ1)) ]) ud = fastfrac(ud) ux1 = fastfrac(ux1) uy1 = fastfrac(uy1) uX1 = fastfrac(uX1) uY1 = fastfrac(uY1) uZ1 = fastfrac(uZ1) uR0 = ((uX1^2)) uR1 = ((uX1+uY1)) uR1 = ((uY1*uR1)) uR2 = ((uZ1+uX1)) uR2 = ((uZ1*uR2)) uR2 = ((uR0+uR2)) uR1 = ((uR0+uR1)) uR0 = ((uX1-uY1)) uR0 = ((uR1*uR0)) uZ3 = ((uR0*uZ1)) uR1 = ((uZ1-uX1)) uR1 = ((uR2*uR1)) uX3 = ((uR1*uY1)) uR2 = ((-(uR0+uR1))) uY3 = ((uR2*uX1)) ux3 = ((uy1*(fastfrac(1)-ux1^3)/(ux1^3-uy1^3))).reduce() uy3 = ((ux1*(uy1^3-fastfrac(1))/(ux1^3-uy1^3))).reduce() print isidentity((ux3^3+uy3^3+fastfrac(1))-(fastfrac(3)*ud*ux3*uy3)) print isidentity((ux3)-(uX3/uZ3)) print isidentity((uy3)-(uY3/uZ3))