name short Weierstrass curves
parameter a2
parameter a6
coordinate x
coordinate y
satisfying y^2 + x y = x^3 + a2 x^2 + a6
addition x = ((y1+y2)/(x1+x2))^2+((y1+y2)/(x1+x2))+x1+x2+a2
addition y = ((y1+y2)/(x1+x2))^3+(x2+a2+1)*((y1+y2)/(x1+x2))+x1+x2+a2+y1
doubling x = (x1+y1/x1)^2 + (x1+y1/x1) + a2
doubling y = (x1+y1/x1)^3 + (x1 + a2 + 1)*(x1+y1/x1) + a2 + y1
negation x = x1
negation y = x1 + y1
toweierstrass weierx = x
toweierstrass weiery = y
a0 = 1
a1 = 1
a2 = a2
a3 = 0
a4 = 0
a6 = a6
fromweierstrass x = weierx
fromweierstrass y = weiery