A man is kayaking down a waterfall.
A man is in a waterfall.
A man is kayaking down a waterfall means he is in waterfall
exists e1 s1 x1 x2.(a_down(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_kayake(e1) & n_waterfall(x2) & n_man(x1))
exists p1 x1.(exists x2.(in(x1,x2) & n_waterfall(x2)) & n_man(x1))