The boy is jumping in the air.
A girl sits on the floor.
A boy is not a girl. One cannot be jumping and sitting at the same time.
exists e1 x1 x2.(n_air(x2) & n_boy(x1) & in(e1,x2) & Actor(e1,x1) & v_jump(e1))
exists e1 x1 x2.(n_floor(x2) & on(e1,x2) & Actor(e1,x1) & v_sit(e1) & n_girl(x1))