A gray bird is flying through the trees.
A bird in a cage.
A bird in a cage is not  flying through the trees.
exists e1 s1 x1 x2.(n_tree(x2) & through(e1,x2) & Actor(e1,x1) & v_fly(e1) & n_bird(x1) & a_gray(s1) & Theme(s1,x1))
exists x1 x2.(a_topic(x1) & in(x1,x2) & n_cage(x2) & n_bird(x1))