Man kayaking in a raging river.
A man is on the river.
The man is on the river because he is kayaking on raging waters.
exists e1 x1 x2 x3.(a_topic(x1) & in(x1,x3) & n_river(x3) & Actor(e1,x3) & v_rage(e1) & n_kayaking(x1) & of(x1,x2) & n_man(x2))
exists p1 x1 x2.(n_river(x2) & on(x1,x2) & n_man(x1))