A child bangs on a set of drums.
The child is part of a band.
A child bangs on drums does not imply to be part of a band.
exists x1 x2 x3 x4.(a_topic(x1) & on(x1,x3) & of(x3,x4) & n_drum(x4) & n_set(x3) & n_bang(x1) & of(x1,x2) & n_child(x2))
exists p1 x1.(n_child(x1) & exists x2 x3.((x1 = x2) & of(x2,x3) & n_band(x3) & n_part(x2)))