A marching band performs on the field.
The marching band is walking down Main Street.
The marching band either performs on a field or they are walking on a street, but not both.
exists e1 x1 x2 x3.(n_field(x3) & a_topic(x1) & on(x1,x3) & n_perform(x1) & of(x1,x2) & n_band(x2) & Actor(e1,x1) & v_march(e1))
exists e1 s1 x1 x2 x3 x4.(ne_per_street(x3) & (x3 = x4) & ne_per_main(x4) & n_band(x1) & of(x1,x2) & n_marching(x2) & a_down(s1) & Manner(e1,s1) & Theme(e1,x3) & Actor(e1,x1) & v_walk(e1))