The bird's feet are grasping the window tightly.
the bird is flying to his nest
The bird bird's feet cannot be grasping the window tightly and flying to his nest 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 e1 x1 x2.(n_nest(x2) & of(x2,x1) & n_male(x1) & n_bird(x1) & to(e1,x2) & Actor(e1,x1) & v_fly(e1))