A man practicing boxing
Sports practicing is doing by a person
boxing is a form of sports practicing.
exists e1 x1 x2 x3.(a_topic(x1) & Actor(e1,x3) & v_box(e1) & (x1 = x3) & n_practicing(x1) & of(x1,x2) & n_man(x2))
exists e1 x1 x2 x3.(by(e1,x3) & n_person(x3) & Actor(e1,x1) & v_do(e1) & n_practicing(x1) & (x1 = x2) & ne_nam_sports(x2))