A player falls on her knees during a roller derby.
A roller derby player sits on the bench.
It is impossible that a roller derby player sits on the bench and falls on her knees simultaneously.
exists e1 x1 x2 x3 x4.(during(e1,x3) & n_derby(x3) & of(x3,x4) & n_roller(x4) & on(e1,x2) & n_knee(x2) & of(x2,x1) & n_female(x1) & Actor(e1,x1) & v_fall(e1) & n_player(x1))
exists e1 x1 x2 x3 x4.(n_bench(x4) & on(e1,x4) & Actor(e1,x1) & v_sit(e1) & n_player(x1) & of(x1,x3) & n_derby(x3) & of(x1,x2) & n_roller(x2))