Children participating in activities on the beach.
Children are at home
You cannot be on the beach if you are at home because you would be inside at home and outside at the beach.
exists e1 x1 x2 x3 x4.(n_beach(x4) & a_topic(x1) & on(e1,x4) & in(e1,x3) & n_activity(x3) & Actor(e1,x2) & v_participate(e1) & (x1 = x2) & n_child(x1))
exists p1 x1.(exists x2.(at(x1,x2) & n_home(x2)) & n_child(x1))