Week 3

The material is getting more challenging and interesting now. We are learning to rewrite English statements symbolically. I found that this required careful thinking, and is slightly confusing at times, but is actually quite fun.

In tutorial exercise #2, I was confused about one question, which said ‘Some courses have the same prerequisites’.  I interpreted this statement to mean that some courses share one or more common prerequisites, so I rewrote it symbolically as

But when the TA went through the questions with us during the tutorial, he put down

which really confused me for a while because I thought that he was wrong. However, I tried to translate this symbolic statement into English, and found that it meant some courses have the same set of prerequisites, and realized that the original English statement in the question could also mean that. Aside from that, I haven’t had much trouble. We’ve started playing around more with the symbols and learned a few laws such as association laws and distributive laws. We have our first assignment now. I’ve taken a look at it, and it seems to require a lot of playing around and thinking about the symbols. I’m really looking forward to working on it, as I find what we are doing now fun. 

Introduction (Week1+2)

We've finished the first week of lectures, and we're approaching the end of the second week. So far I'm finding the content quite easy to understand. Mostly, we've been looking at various statements and determining whether they are true or false, studying the way quantifiers work, and using Venn diagrams to help us solve problems. I have learned the importance of being precise, and that you have to be really careful with natural language, as it can be quite ambiguous. 

When going over the lecture slides, I was confused for a while with the word 'any' in the following function:

def q1(S1, S2):

    ''' (set, set)  -> bool

    Return whether ...

    '''

    return any ({x in S2 for x in S1})

'Any' could mean that within a given set, any element will return true for a certain statement (basically meaning all of them will return true), or it could mean whether there are any elements in the given set that will return true for the statement (if there exists one or more elements that will return true for the statement). In the end, I tested the function out in Python shell and learned that it had the latter meaning. 

Overall, I'm finding CSC165 to be quite enjoyable. Content is a little too simple at the moment, but I'm sure it gets more challenging later on.