source 2008 Bernstein--Lange--Rezaeian Farashahi
parameter e
parameter f
assume e^2 = d1
assume f^2 = d2/d1 + 1
compute A = W2 W3
compute B = Z2 Z3
compute C = (W2+Z2)(W3+Z3)
compute W5 = Z1(d1(C+A+B)^2)
compute Z5 = W1(A C+(e B+f A)^2)