source 1998 Cohen--Miyaji--Ono "Efficient elliptic curve exponentiation using mixed coordinates", formula (3), plus common-subexpression elimination
compute Y1Z2 = Y1 Z2
compute X1Z2 = X1 Z2
compute Z1Z2 = Z1 Z2
compute u = Y2 Z1-Y1Z2
compute uu = u^2
compute v = X2 Z1-X1Z2
compute vv = v^2
compute vvv = v vv
compute R = vv X1Z2
compute A = uu Z1Z2-vvv-2 R
compute X3 = v A
compute Y3 = u(R-A)-vvv Y1Z2
compute Z3 = vvv Z1Z2