Two boys flip in the air.
The boys are sleeping on a couch.
You cannot flip in the air at the same time you are sleeping.
exists e1 x1 x2.(n_air(x2) & in(e1,x2) & Actor(e1,x1) & v_flip(e1) & n_boy(x1) & card_eq_2(x1))
exists e1 x1 x2.(n_boy(x1) & on(e1,x2) & n_couch(x2) & Actor(e1,x1) & v_sleep(e1))