(CSC165)_Sep 20th_Logic XD

I really enjoy studying logic related topics. Although I have learned most of the content of this week when I was in high school back in China, it is still amazing to learn it in a different language and especially with excellent examples. However, the problems including conduction of two statements and negation are new to me.

A tricky word introduced in the class is 'unless', and if we try to think about it in logic directly, it will be very confusing. However, we can translate it to 'if not' to help us understand. For example:

Do not go, unless you are crazy.

Do not go, if you are not crazy.

not crazy => not go

go => crazy      

I think we can generalize it using P and Q:

P unless Q

P if not Q

P => not Q

Q => not P

Q if not P

So, to sum up, we can translate P unless Q to: (1) P if not Q (2) Q if not P.