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,6,order='invlex') I = R.ideal([ mynumerator((ux1^2+uy1^2)-(uc^2*(1+ud*ux1^2*uy1^2))) , mynumerator((ux2^2+uy2^2)-(uc^2*(1+ud*ux2^2*uy2^2))) ]) J = I + R.ideal([0 , ux1-ux2 , uy1-uy2 ]) uc = fastfrac(uc) ud = fastfrac(ud) ux1 = fastfrac(ux1) uy1 = fastfrac(uy1) ux2 = fastfrac(ux2) uy2 = fastfrac(uy2) ux3 = (((ux1*uy2+uy1*ux2)/(uc*(fastfrac(1)+ud*ux1*ux2*uy1*uy2)))).reduce() uy3 = (((uy1*uy2-ux1*ux2)/(uc*(fastfrac(1)-ud*ux1*ux2*uy1*uy2)))).reduce() ux4 = (((ux1*uy1+uy1*ux1)/(uc*(fastfrac(1)+ud*ux1*ux1*uy1*uy1)))).reduce() uy4 = (((uy1*uy1-ux1*ux1)/(uc*(fastfrac(1)-ud*ux1*ux1*uy1*uy1)))).reduce() a0 = fastfrac((fastfrac(1)/(fastfrac(1)-ud*uc^4))) a1 = fastfrac((fastfrac(0))) a2 = fastfrac((fastfrac(4)/(fastfrac(1)-ud*uc^4)-fastfrac(2))) a3 = fastfrac((fastfrac(0))) a4 = fastfrac((fastfrac(1))) a6 = fastfrac((fastfrac(0))) wu1 = (((uc+uy1)/(uc-uy1))).reduce().sreduce() wv1 = ((fastfrac(2)*uc*(uc+uy1)/(ux1*(uc-uy1)))).reduce().sreduce() print isidentity(a0*(wv1^2)+a1*(wu1*wv1)+a3*wv1-(((wu1+a2)*wu1+a4)*wu1+a6)) print isidentity(ux1-(fastfrac(2)*uc*wu1/wv1)) print isidentity(uy1-(uc*(wu1-fastfrac(1))/(wu1+fastfrac(1)))) wu2 = (((uc+uy2)/(uc-uy2))).reduce().sreduce() wv2 = ((fastfrac(2)*uc*(uc+uy2)/(ux2*(uc-uy2)))).reduce().sreduce() wu3 = (((uc+uy3)/(uc-uy3))).reduce().sreduce() wv3 = ((fastfrac(2)*uc*(uc+uy3)/(ux3*(uc-uy3)))).reduce().sreduce() wu4 = (((uc+uy4)/(uc-uy4))).reduce().sreduce() wv4 = ((fastfrac(2)*uc*(uc+uy4)/(ux4*(uc-uy4)))).reduce().sreduce() slope = ((wv2-wv1)/(wu2-wu1)).reduce().sreduce() print isidentity(a0*slope^2+a1*slope-a2-wu1-wu2-wu3) print isidentity(slope*(wu1-wu3)-wv1-a1*wu3-a3-wv3) slope = ((fastfrac(3)*wu1^2+fastfrac(2)*a2*wu1+a4-a1*wv1)/(fastfrac(2)*a0*wv1+a1*wu1+a3)).reduce().sreduce() print isidentity(a0*slope^2+a1*slope-a2-wu1-wu1-wu4) print isidentity(slope*(wu1-wu4)-wv1-a1*wu4-a3-wv4)