source 1986 Chudnovsky--Chudnovsky "Sequences of numbers generated by addition in formal groups and new primality and factorization tests", formula 4.9ii, plus common-subexpression elimination
compute C1Z1 = C1 Z1
compute C1D1 = C1 D1
compute D1Z1 = D1 Z1
compute D1S1 = D1 S1
compute U = C1Z1^2
compute V = C1D1^2
compute W = D1Z1^2
compute UV = U-V
compute S3 = 2 C1Z1 D1S1
compute C3 = U-W+V
compute D3 = W-UV
compute Z3 = W+UV
compute SC3 = S3 C3
compute DZ3 = D3 Z3