defensive player waiting for the snap
A person playing football
A player is a person.  Since the player is waiting for the snap, this implies that the player is playing football.
exists e1 s1 x1 x2.(n_snap(x2) & for(e1,x2) & Actor(e1,x1) & v_wait(e1) & n_player(x1) & a_defensive(s1) & Theme(s1,x1))
exists e1 x1 x2 x3.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_playing(e1) & n_football(x3) & (x1 = x2) & n_person(x1))