A generating process for the Trotter product of stochastic semigroups

We find the form of the generating processW_t for the Trotter productX_s^t Z_s^t of stochastic semigroups:W_t=Y_t+V_t+[Y, V]_t, whereY_t andV_t are generating processes of the semigroupsX_s^t andZ_s^t respectively and [Y, V]_t is their mutual quadratic variation.Translated fromTeoriya Sluchaínykh Protsessov, Vol. 14, pp. 94–96, 1986.