We consider a one-dimensional nearest-neighbour interacting particle system
, which is a mixture of the simple exclusion process and the voter model. T
he state space is taken to be the countable set of the configurations that
have a finite number of particles to the right of the origin and a finite n
umber of empty sites to the left of it. We obtain criteria for the ergodici
ty and some other properties of this system using the method of Lyapunov fu
nctions.