source 2008 Bernstein--Lange--Rezaeian Farashahi
appliesto wz-1
assume Z1 = 1
compute C = W2(Z2+W2)
compute D = W3(Z3+W3)
compute E = Z2 Z3
compute V = C D
compute U = V + d1 E^2
compute W5 = V + W1 U
compute Z5 = U