Boolean Logic and Monotonicity

• This kind of logic has a problem: it must remain consistent.
• Remember that any rule of the form if False then anything is valid.
• So, if pigs fly then I am the smartest man on the planet. That's a true statment
• For a logical KB to remain consistent, it can't have X and not(X)
• If it does, then anything can be concluded.
• You can make up if clauses of the form if (X and not(X)) then Y, to conclude any Y.
• Standard Logic is monotonic. What you know can never be taken away.
• It seems that humans are non-monotonic. We can hold a belief and later change that belief.
• This is one of the problems of a boolean system.
• Still, boolean systems can go a long way to approximating the real world.