A baseball catcher catches a ball while the umpire watches.
A football player drops the ball
One cannot be a football player and baseball catcher at the same time.
exists e1 x1 x2 x3 x4 x5.(n_watch(x4) & of(x4,x5) & n_umpire(x5) & while(e1,x4) & Theme(e1,x3) & Actor(e1,x1) & v_catch(e1) & n_ball(x3) & n_catcher(x1) & of(x1,x2) & n_baseball(x2))
exists e1 x1 x2 x3.(n_ball(x3) & Theme(e1,x3) & Actor(e1,x1) & v_drop(e1) & n_player(x1) & of(x1,x2) & n_football(x2))