701.85/299.39	MAYBE
701.85/299.39	
701.85/299.39	Problem:
701.85/299.39	 strict:
701.85/299.39	  top(old(x)) -> top(check(x))
701.85/299.39	  top(new(x)) -> top(check(x))
701.85/299.39	 weak:
701.85/299.39	  bot() -> new(bot())
701.85/299.39	  check(new(x)) -> new(check(x))
701.85/299.39	  check(old(x)) -> old(check(x))
701.85/299.39	  check(old(x)) -> old(x)
701.85/299.39	
701.85/299.39	Proof:
701.85/299.39	 Open
701.85/299.39	EOF