Guy plays guitar at a concert.
The man is practicing playing the drums.
Guitar and drums are not the same instrument.
exists e1 x1 x2 x3.(ne_nam_guy(x1) & at(e1,x3) & n_concert(x3) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_guitar(x2))
exists e1 p1 x1 x2.(n_drum(x2) & n_man(x1) & exists e2.(Theme(e2,x2) & Actor(e2,x1) & v_play(e2)) & Topic(e1,p1) & Actor(e1,x1) & v_practice(e1))