week 4 topics

In week 4( Oct2-4), we learned about apply, booleans, and more booleans and list functions. It is easy to understand "And" "Or" "Not". In the past tests'  question 1 is related to booleans. The most interesting thing I found was that function design and use check-expect to check whether the two expressions are the same. However, I don't like function "map" and "apply", it is complicated for me and I need to spend much time writing intermediate steps.