Kids forming a rock band.
Kids are playing guitars.
If they are in a rock band then they are playing guitars.
exists e1 x1 x2 x3 x4.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_form(e1) & n_band(x3) & of(x3,x4) & n_rock(x4) & (x1 = x2) & n_kid(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_guitar(x2) & n_kid(x1))