People are fishing on the beach.
People are fishing for trout.
People could be fishing for different kinda of fish than trout.
exists e1 x1 x2.(n_beach(x2) & on(e1,x2) & Actor(e1,x1) & v_fish(e1) & n_people(x1))
exists e1 x1 x2.(for(e1,x2) & n_trout(x2) & Actor(e1,x1) & v_fish(e1) & n_people(x1))