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),8,order='invlex') I = R.ideal([ mynumerator((ud1*(ux1+uy1)+ud2*(ux1^2+uy1^2))-((ux1+ux1^2)*(uy1+uy1^2))) , mynumerator((ux1)-(uX1/uZ1)) , mynumerator((uy1)-(uY1/uZ1)) , mynumerator((ud1)-(ud2)) , mynumerator((ud2d1)-(ud2/ud1)) ]) ud2d1 = fastfrac(ud2d1) ud1 = fastfrac(ud1) ud2 = fastfrac(ud2) ux1 = fastfrac(ux1) uy1 = fastfrac(uy1) uX1 = fastfrac(uX1) uY1 = fastfrac(uY1) uZ1 = fastfrac(uZ1) uA = ((uX1^2)) uB = ((uA^2)) uC = ((uY1^2)) uD = ((uC^2)) uE = ((uZ1^2)) uF = ((ud1*uE^2)) uG = ((ud2d1*(uB+uD))) uH = ((uA*uE)) uI = ((uC*uE)) uJ = ((uH+uI)) uK = ((uG+ud2*uJ)) uZ3 = ((uF+uJ+uG)) uX3 = ((uK+uH+uD)) uY3 = ((uK+uI+uB)) ux3 = (((ud1*(ux1+ux1)+ud2*(ux1+uy1)*(ux1+uy1)+(ux1+ux1^2)*(ux1*(uy1+uy1+fastfrac(1))+uy1*uy1))/(ud1+(ux1+ux1^2)*(ux1+uy1)))).reduce() uy3 = (((ud1*(uy1+uy1)+ud2*(ux1+uy1)*(ux1+uy1)+(uy1+uy1^2)*(uy1*(ux1+ux1+fastfrac(1))+ux1*ux1))/(ud1+(uy1+uy1^2)*(ux1+uy1)))).reduce() print isidentity((ud1*(ux3+uy3)+ud2*(ux3^2+uy3^2))-((ux3+ux3^2)*(uy3+uy3^2))) print isidentity((ux3)-(uX3/uZ3)) print isidentity((uy3)-(uY3/uZ3))