Four boys are playing at a playground
Kids are playing.
Kids can be another term for boys.
exists e1 x1 x2.(at(e1,x2) & n_playground(x2) & Actor(e1,x1) & v_play(e1) & n_boy(x1) & card_eq_4(x1))
exists e1 x1.(Actor(e1,x1) & v_play(e1) & n_kid(x1))