A boy holds a picture over his head.
picture on head
holding over head does not mean on head
exists e1 x1 x2 x3.(over(e1,x3) & n_head(x3) & of(x3,x1) & n_male(x1) & Theme(e1,x2) & Actor(e1,x1) & v_hold(e1) & n_picture(x2) & n_boy(x1))
exists x1 x2.(a_topic(x1) & on(x1,x2) & n_head(x2) & n_picture(x1))