two guys in street cloths doing some marshal arts.
A couple of guys challenge each other to marshal arts in their street clothes.
The two guys doing martial arts do not necessarily challenge one another.
exists e1 s1 x1 x2 x3 x4 x5.(a_topic(x1) & Theme(e1,x5) & Actor(e1,x4) & v_do(e1) & n_art(x5) & a_marshal(s1) & Theme(s1,x5) & (x1 = x4) & in(x1,x2) & n_cloth(x2) & of(x2,x3) & n_street(x3) & n_guy(x1) & card_eq_2(x1))
exists x1 x2 x5 x6.(all x3.(n_other(x3) -> exists e1 s1 x4.(to(e1,x4) & in(x4,x5) & n_art(x4) & a_marshal(s1) & Theme(s1,x4) & Theme(e1,x3) & Actor(e1,x1) & v_challenge(e1))) & n_clothes(x5) & of(x5,x6) & n_street(x6) & of(x5,x1) & n_thing(x1) & of(x1,x2) & n_guy(x2) & n_couple(x1))