A black-haired man plays a guitar.
A black-haired man is playing the piano.
A guitar and piano are two completely different instruments.
exists e1 s1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_guitar(x2) & n_man(x1) & a_black-haired(s1) & Theme(s1,x1))
exists e1 s1 x1 x2.(n_piano(x2) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_man(x1) & a_black-haired(s1) & Theme(s1,x1))