A group of kids have a pillow-fight.
Kids are eating lunch
The children can either be having a pillow fight or eating lunch. They cannot be doing both at the same time.
exists e1 x1 x2 x3.(Theme(e1,x3) & Actor(e1,x1) & v_have(e1) & n_pillow-fight(x3) & of(x1,x2) & n_kid(x2) & n_group(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_eat(e1) & n_lunch(x2) & n_kid(x1))