Week 1

At the first few lectures of first week of CSC165, I had to admit that I was kind of lost, not only because my native language WAS not english, but also because my brain couldn't get the logics that professor mentioned in lectures. I tried catching up and understanding different terminologies such as some, not some, all, not all, any, not any, counter example, qualifiers, universal claim(∀), existence claims(∃), and many others. By the end of first week, I found myself starting to understand the materials progressively as I was able to connect some topics from CSC165 to what I learned in CSC108.

For example: 

def q0(S1,S2):
    return not all{x in S2 for x in S1}

Here are some notes that I took in various lectures and tutorial:

"Some" means at least one or more.
"Not Some" can mean all or none (nothing).
"All" means everything.
"Not All" means anything more than 0.

any({...}) returns True if the set has one or more True elements

all ({...}) returns True if the set has True elements

I understood there were various methods that would help me when I drew venn diagrams.

All False -- > give one solution (counterexample)

All True --> give all solutions to prove the function 

Some False--> give all solutions to prove the function

Some True --> give one counterexample 

While drawing venn diagrams (four regions in total):

Cross - "X" means this region must be empty. 

Circle -"O" means this region must be occupied. 

Emptiness - "    " means this region doesn't matter.