Solvable multi-species reaction-diffusion processes, including the   extended drop-push model
  By considering the master equation of asymmetric exclusion process on a one-dimensional lattice, we obtain the most general boundary condition of the multi-species exclusion processes in which the number of particles is constant in time. This boundary condition introduces the various interactions to the particles, including ones which have been studied yet and the new ones. In these new models, the particles have simultaneously diffusion, the two-particle interactions $A_\alpha A_\beta\to A_\gamma A_\delta$, and the $n$-particle extended drop-push interaction. The constraints on reaction rates are obtained and in two-species case, they are solved to obtain a solvable model. The conditional probabilities of this model are calculated. 
Masoud Alimohammadi