A = X1^2 t0 = X1+Y1 B = Y1*t0 C = A+B t1 = Z1+X1 D = Z1*t1 E = A+D t2 = X1-Y1 F = C*t2 t3 = Z1-X1 G = E*t3 Z3 = F*Z1 t4 = F+G t5 = t4*X1 Y3 = -t5 X3 = G*Y1