source 2008 Sutherland compute U = 2 Y1 compute V = U^2 compute W = U V compute S = X1 V compute M = 3 X1^2+a ZZ1^2 compute X3 = M^2-2 S compute Y3 = M (S-X3)-W Y1 compute ZZ3 = V ZZ1 compute ZZZ3 = W ZZZ1