A dog with a ball in its mouth sitting outside.
The dog has a frisbee in its mouth.
a ball is not a frisbee and can only have one in the mouth at a time
exists e1 p1 x1 x2 x3 x4.(a_topic(x1) & with(x1,x2) & in(x2,x3) & exists s1.(Theme(s1,x4) & a_outside(s1)) & Topic(e1,p1) & Actor(e1,x4) & v_sit(e1) & (x3 = x4) & n_mouth(x3) & of(x3,x1) & n_thing(x1) & n_ball(x2) & n_dog(x1))
exists e1 x1 x2 x3.(n_mouth(x3) & of(x3,x1) & n_thing(x1) & n_dog(x1) & Theme(e1,x2) & Actor(e1,x1) & v_have(e1) & in(x2,x3) & n_frisbee(x2))