The reason is that the condition for firing Rule 2 that was once true is not true anymore because it references an object (objectB) that is no longer part of the knowledge.

Another rule prevents businesses from firing women for two years after they become pregnant-creating an incentive to fire them earlier, or not to hire women of childbearing age at all.

His rule cost the lives of perhaps half a million Iraqis. Two-thirds fell in unnecessary wars; the rest were civilian “enemies”, rounded up and shot, usually by firing squad.