Four people performing music outdoors.
The musicians are outside.
The four people performing music are musicians. They are outdoors so they are outside.
exists e1 x1 x2 x3 x4.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_perform(e1) & n_outdoors(x3) & of(x3,x4) & n_music(x4) & (x1 = x2) & n_people(x1) & card_eq_4(x1))
exists s1 x1.(n_musician(x1) & Theme(s1,x1) & a_outside(s1))