R1 = X1 R2 = Y1 R3 = Z1 R4 = R3^2 R3 = R2*R3 R3 = 2*R3 R4 = R4^2 R4 = a*R4 R5 = R1^2 R4 = R4+R5 R5 = 2*R5 R4 = R4+R5 R2 = 2*R2 R2 = R2^2 R5 = R2^2 R5 = half*R5 R2 = R2*R1 R1 = R4^2 R1 = R1-R2 R1 = R1-R2 R2 = R2-R1 R2 = R2*R4 R2 = R2-R5 X3 = R1 Y3 = R2 Z3 = R3