A gray bird is flying through the trees.
The blue bird is on the grass.
A gray bird is not blue. A bird  flying through the trees is not on the grass.
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 p1 s1 x1 x2.(n_grass(x2) & n_bird(x1) & a_blue(s1) & Theme(s1,x1) & on(x1,x2))