A construction worker pulls a whaler.
the man is pushing a stack of boxes onto a skid
One cannot be pushing while he pulls simultaneously.
exists e1 x1 x2 x3.(Theme(e1,x3) & Actor(e1,x1) & v_pull(e1) & n_whaler(x3) & n_worker(x1) & of(x1,x2) & n_construction(x2))
exists e1 x1 x2 x3 x4.(n_man(x1) & onto(e1,x4) & n_skid(x4) & Theme(e1,x2) & Actor(e1,x1) & v_push(e1) & of(x2,x3) & n_box(x3) & n_stack(x2))