A = X1^2 B = Y1^2 D = A+B t0 = X1+Y1 t1 = t0^2 G = t1-D t2 = 2*Y1 t3 = t2-G t4 = X1+A t5 = t4+1 X3 = t3*t5 t6 = 2*X1 t7 = G-t6 t8 = Y1+B t9 = t8+1 Y3 = t7*t9 t10 = 2*D t11 = X1-Y1 t12 = G+t10 Z3 = t11*t12