There are many children working on different activities in the classroom.
Children at recess.
The children would not be in the working in the classroom at recess.
exists p1 x1 x5 x6.(n_classroom(x6) & n_activity(x5) & exists e1 x2 x3 x4.((x1 = x2) & in(e1,x6) & on(e1,x4) & -(x4 = x5) & n_activity(x4) & Actor(e1,x3) & v_work(e1) & (x2 = x3) & n_child(x2) & n_quantity(x2)))
exists x1 x2.(a_topic(x1) & at(x1,x2) & n_recess(x2) & n_child(x1))