Formal languages, FSA

I was completely new to regular expressions. We were introduced to regex from both the theoretical perspective in csc236, and in the practical usage perspective in csc207, at the same time.

I think this concurrent introduction from both perspectives helped quicken my learning, and I got familiar with regex pretty quick. The theoretical perspective is still harder for me though. Some regex proofs seem to require multiple induction, and it can get confusing as the concepts are quite abstract.

FSAs are quite interesting, I like its graphical nature. It is very interesting that every regex has an FSA (if we allow epsilon transitions). All in all, I really like this part of the course.

A3 is due at a really bad time though. It's another crazy week..

Convincing Myself, and some Fundamentals

After finishing Q3 of a1, I had lingering thoughts about a certain part of the proof - I wasn't fully convinced that it works. I kept wondering if I needed induction to justify the implication, or if doing that is unnecessary and what I have is sufficient.

A dose of the very helpful Danny's Office Hour gave me the answer.
So, I believe the lesson today is that if I'm not fully convinced myself, I need to do more work on justifying the part of concern.

Danny also pointed out some problems with "big jumps" and generality issues. I think I had an idea of what he meant, but wasn't entirely sure.

As I worked on adding the induction proof, I encountered very similar generality issues, having to do with fundamental definitions of natural numbers, integers. It was then that I realized what Danny meant, and understood the importance of these fundamental definitions that I never really internalized.

So, the second lesson today is, even if I feel like I'm convinced, it may not be due to correct understanding, and so it's a good idea to visit Danny or a TA to check my works.

a1 and Renewed Concern

Since the beginning of the term, I've gained a deeper understanding of Zen and Zen practice. Now, I should replace the word "unease" with the more accurately representative word "concern".

I really liked the way a1 questions are structured. It was challenging, but not overly so. Q1 and Q2 challenged me in putting ideas in formal language. Q3 is a great question, I love the structure and the way it guides into an elegant proof.

At this point after finishing A1 (minus Q4), I feel a sense of accomplishment, and a new level of acuteness in my logical sense.

The honeymoon feeling is quickly over, such is the norm during the school-year. I'm not even sure I understand the definition of a ternary tree in a1Q4 yet, and recursion wasn't easy for me in 148 when I took it several years ago. But, that was the immature and irresponsible me several years ago, with a terrible work ethic.

I'm also slightly concerned about the structure of tests in 236. Sometimes insights to proofs come in seconds, sometimes several minutes, and sometimes sleeping on it works wonders. It all seems rather arbitrary. Will the test structure be able to accurately represent a student's level of understanding?