Two young boys practicing the art of karate.
Boys are learning karate to defend themselves.
The boys could be practicing karate for many other reasons other than to defend themselves.
exists e1 s1 x1 x2 x3 x4.(n_art(x3) & a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_practice(e1) & of(x3,x4) & n_karate(x4) & (x1 = x2) & n_boy(x1) & a_young(s1) & Theme(s1,x1) & card_eq_2(x1))
exists e1 p1 x1 x2 x3 x4.(n_group(x4) & Topic(e1,p1) & exists e2.(Theme(e2,x4) & Actor(e2,x1) & v_defend(e2)) & Theme(e1,x3) & Actor(e1,x2) & v_learn(e1) & n_karate(x3) & n_boy(x2) & n_boy(x1))