MAYBE
234.42/58.97	MAYBE
234.42/58.97	
234.42/58.97	Problem:
234.42/58.97	 top(free(x)) -> top(check(new(x)))
234.42/58.97	 new(free(x)) -> free(new(x))
234.42/58.97	 old(free(x)) -> free(old(x))
234.42/58.97	 new(serve()) -> free(serve())
234.42/58.97	 old(serve()) -> free(serve())
234.42/58.97	 check(free(x)) -> free(check(x))
234.42/58.97	 check(new(x)) -> new(check(x))
234.42/58.97	 check(old(x)) -> old(check(x))
234.42/58.97	 check(old(x)) -> old(x)
234.42/58.97	
234.42/58.97	Proof:
234.42/58.97	 Open
234.42/58.98	EOF