a lot of kids swimming in the river
Children are in the water.
Children who are swimming in the river
exists e1 x1 x2 x3 x4.(n_river(x4) & a_topic(x1) & of(x1,x2) & in(e1,x4) & Actor(e1,x3) & v_swim(e1) & (x2 = x3) & n_kid(x2) & n_lot(x1))
exists p1 x1 x2.(n_water(x2) & in(x1,x2) & n_child(x1))