The bird's feet are grasping the window tightly.
The bird is in a metal cage.
The bird cannot be grasping the window tightly with its feet and in a metal cage at the same time.
exists e1 s1 x1 x2 x3.(n_window(x3) & n_foot(x2) & of(x2,x1) & n_bird(x1) & a_tightly(s1) & Manner(e1,s1) & Theme(e1,x3) & Actor(e1,x2) & v_grasp(e1))
exists p1 x1.(n_bird(x1) & exists x2 x3.(in(x1,x2) & n_cage(x2) & of(x2,x3) & n_metal(x3)))