A gray bird is flying through the trees.
A bird is in the sky.
The bird that is in the trees is also flying in the sky.
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 x1 x2.(n_sky(x2) & in(x1,x2) & n_bird(x1))