A bird flying pass the walkway.
bird is flying
These sentences seem to be incomplete, but one bird is flying by the walkway while the other is just flying.
exists e1 e2 x1 x2 x3.(n_walkway(x3) & Theme(e2,x3) & Actor(e2,x1) & v_pass(e2) & Actor(e1,x2) & v_fly(e1) & (x1 = x2) & n_bird(x1))
exists e1 x1.(Actor(e1,x1) & v_fly(e1) & n_bird(x1))