WEEK 4

What I Learnt

         This week’s lecture covered bi-implication, transitivity, mixed quantifiers and the beginning of proof. For now, I could use the manipulation rules and understood the negation part quite well, so it was comparative easy for me to absorb the concepts of bi-implication, transitivity. As for mixed quantifiers, the example professor used was the definition of limit, which I have learnt in MAT137. 

What enlightened me was our professor used another way to teach this definition. Therefore, I became able to treat this definition in a total different angle, and understood it secondly and deeply.

We were also taught how to start a proof and the structure of the proof:

It was a brand-new part for me, and I thought I needed more practice to familiar with this standard structure and to handle it. And I could also apply this part into my MAT137 to perfect my proof. By the way, through yojello’s slog (http://165slogs.blogspot.ca/2014/10/slog-week-4-you-want-proof-you-cant.html), I found we had the same confusion about how to see the connection between the initial part and the final part. The questions she listed gave me lots of advices about what I should focus on and learn in this chapter.

Assignment 1 and Difficulty

My group finished our first assignment in CSC165. Yahui Liu was my one of members in our group, so I had some same feelings with her (http://yahuiliuslog165.blogspot.ca/2014/10/week-4.html). The time spent much more than we expected (about two days), which explored our problems in understanding knowledge and using the skills we learnt. We learnt again the slides and course notes, discussed with each other, and also consulted to upper year students, during which we learnt some knowledge we missed, and corrected some we misunderstood.

Our difficulty was mainly on the 4th question:

According to the solution, every question had two situations separately. However, we only figured out one situation in each question. We only regarded D as the universe of P and Q, but missed the second situation. I thought more practice would tell me how to apply Venn diagram more precisely and flexibly in this kind of problem-solving.