For example, ¬ ◻ F → ¬ F {\displaystyle \neg \Box F\rightarrow \neg F} means that F {\displaystyle F} is assumed false if it is not known to be true.
例如， ¬ ◻ F → ¬ F {\displaystyle \neg \Box F\rightarrow \neg F} 意味着如果不知道 F {\displaystyle F} 是真的，则假定它为假。