A man is playing an acoustic guitar.
A man is in competition for guitar.
Not all man playing an acoustic guitar is in competition.
exists e1 s1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_guitar(x2) & a_acoustic(s1) & Theme(s1,x2) & n_man(x1))
exists p1 x1.(exists x2 x3.(in(x1,x2) & for(x2,x3) & n_guitar(x3) & n_competition(x2)) & n_man(x1))