Young hockey players play on rollerskates.
Children play street hockey.
Not all young hockey players are children.
exists e1 s1 x1 x2 x3.(on(e1,x3) & n_rollerskate(x3) & Actor(e1,x1) & v_play(e1) & n_player(x1) & of(x1,x2) & n_hockey(x2) & a_young(s1) & Theme(s1,x1))
exists e1 x1 x2 x3.(Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_hockey(x2) & of(x2,x3) & n_street(x3) & n_child(x1))