a lot of kids swimming in the river
The river has alligators.
Not every river has alligators.
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 e1 x1 x2.(n_river(x1) & Theme(e1,x2) & Actor(e1,x1) & v_have(e1) & n_alligator(x2))