A man with a backpack running downhill.
A man is moving quickly downward.
A man running is moving fast for a human, especially when going downhill. Thus the man is moving quickly downward.
exists e1 x1 x2 x3.(a_topic(x1) & with(x1,x2) & n_downhill(x2) & Actor(e1,x2) & v_run(e1) & of(x2,x3) & n_backpack(x3) & n_man(x1))
exists e1 s1 s2 x1.(a_downward(s2) & Manner(e1,s2) & a_quickly(s1) & Manner(e1,s1) & Actor(e1,x1) & v_move(e1) & n_man(x1))