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,5,order='invlex') I = R.ideal([ mynumerator((uy1^2)-(ux1^3+ua*ux1^2+16*ua*ux1)) , mynumerator((uy2^2)-(ux2^3+ua*ux2^2+16*ua*ux2)) ]) J = I + R.ideal([0 , ux1-ux2 , uy1-uy2 ]) ua = fastfrac(ua) ux1 = fastfrac(ux1) uy1 = fastfrac(uy1) ux2 = fastfrac(ux2) uy2 = fastfrac(uy2) ux3 = (((-ux1^3+(ux2-ua)*ux1^2+(ux2^2+fastfrac(2)*ua*ux2)*ux1+(uy1^2-fastfrac(2)*uy2*uy1+(-ux2^3-ua*ux2^2+uy2^2)))/(ux1^2-fastfrac(2)*ux2*ux1+ux2^2))).reduce() uy3 = ((((-uy1+fastfrac(2)*uy2)*ux1^3+(-ua*uy1+(-fastfrac(3)*uy2*ux2+ua*uy2))*ux1^2+((fastfrac(3)*ux2^2+fastfrac(2)*ua*ux2)*uy1-fastfrac(2)*ua*uy2*ux2)*ux1+(uy1^3-fastfrac(3)*uy2*uy1^2+(-fastfrac(2)*ux2^3-ua*ux2^2+fastfrac(3)*uy2^2)*uy1+(uy2*ux2^3+ua*uy2*ux2^2-uy2^3)))/(-ux1^3+fastfrac(3)*ux2*ux1^2-fastfrac(3)*ux2^2*ux1+ux2^3))).reduce() ux4 = ((fastfrac(1)/(fastfrac(4)*uy1^2)*ux1^4-fastfrac(8)*ua/uy1^2*ux1^2+fastfrac(64)*ua^2/uy1^2)).reduce() uy4 = ((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() a0 = fastfrac((fastfrac(1))) a1 = fastfrac((fastfrac(0))) a2 = fastfrac((ua)) a3 = fastfrac((fastfrac(0))) a4 = fastfrac((fastfrac(16)*ua)) a6 = fastfrac((fastfrac(0))) wu1 = ((ux1)).reduce().sreduce() wv1 = ((uy1)).reduce().sreduce() print isidentity(a0*(wv1^2)+a1*(wu1*wv1)+a3*wv1-(((wu1+a2)*wu1+a4)*wu1+a6)) print isidentity(ux1-(wu1)) print isidentity(uy1-(wv1)) wu2 = ((ux2)).reduce().sreduce() wv2 = ((uy2)).reduce().sreduce() wu3 = ((ux3)).reduce().sreduce() wv3 = ((uy3)).reduce().sreduce() wu4 = ((ux4)).reduce().sreduce() wv4 = ((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)