A person kayaking in strong currents.
The kayaker is enjoying the thrill and challenge of the strong current.
The person kayaking could be struggling to survive in strong currents instead of enjoying the thrill and challenge, so there is nothing to imply that he is in fact enjoying it.
exists e1 s1 x1 x2 x3.(a_topic(x1) & in(e1,x3) & n_current(x3) & a_strong(s1) & Theme(s1,x3) & Actor(e1,x2) & v_kayake(e1) & (x1 = x2) & n_person(x1))
exists e1 s1 x1 x2 x3 x4 x5.(n_current(x5) & a_strong(s1) & Theme(s1,x5) & n_challenge(x4) & n_thrill(x3) & subset_of(x4,x2) & subset_of(x3,x2) & n_kayaker(x1) & Theme(e1,x2) & Actor(e1,x1) & v_enjoy(e1) & of(x2,x5))