A dog is catching a ball.
The cat is playing ball
It can not be both a dog and a cat.
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_catch(e1) & n_ball(x2) & n_dog(x1))
exists e1 x1 x2.(n_cat(x1) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_ball(x2))