The children are playing a game of checkers.
Children at the park amuse themselves with checkers
It cannot be inferred from sentence 1 that the children are at the park.
exists e1 x1 x2 x3.(n_child(x1) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & of(x2,x3) & n_checkers(x3) & n_game(x2))
exists x1 x2 x3 x4.(n_amuse(x2) & of(x2,x3) & n_park(x3) & a_topic(x1) & at(x1,x2) & with(x2,x4) & n_checkers(x4) & n_person(x2) & n_child(x1))