This article has only been invoked once: on September 12, 2001, in response to the 9/11 attacks on the United States.

Once invoked against foreign colonialists, the same principle could also be turned with relative ease against fellow Algerians.

Once invoked, there is no turning back from a bound fork prophecy.

The Third Amendment was once invoked as helping establish an implicit right to privacy in the Constitution.

The name of Brian Boru had been invoked not once, but repeatedly.

It's impossible because once invoked, the elephant image cannot be unthought.

The 16 hour rule may be invoked once per 34 hour reset, if the 5 day pattern has been established.

The Sixth Amendment right to counsel is offense-specific, and cannot be invoked once for all future prosecutions.

Once invoked, it can either work just like alt-tab or you can use your mouse wheel to flip through all of the windows.

Once invoked, logic was like a god.