Assignment Two

Assignment two took a lot longer than I had anticipated. Thinking that the assignment was due at 10am Monday morning, one of my group partners and I spent most of the weekend going over the questions, breaking it down, analyzing it and then finally coming to a conclusion and selecting an appropriate type of proof method to use. From the first assignment, I've learned that though we are no longer required to write up a formal proof, it is still necessary to include most of the proof structure and details which is where we lost the most marks.

In my opinion, the first and last questions where the most difficult. The ternary tree required some time to determing a recursive pattern which did not end up being as complex as it seemed at first. After realizing the pattern, it was still difficult to explain it in a clear and concise manner. This is when my partner and I went through it step by step to seek the best way to approach the proof. We decicded structural induction fit the problem the best. The last question required code tracing in python. The square-root function threw me off a little at first as I didn't see what its purpose was which made me conclude that the program was not correct. Upon a closer analysis and the hints provided on the bulletin board, it then became clear that the program seemed correct.

Hopefully we did better on this assignment than we had done in the last!

Guest Lecturer and Python

Today's lecture was particularly interesting and enjoyful, especially after a long night of assignments and studying. The guest lecturer, Nick, was quite entertaining to say the least. Though I would have liked more material to be covered over the course of the lecture, it was fun, overall. The concepts from today's lecture was easily grasped since many of us have programmed prior to taking the course and so learning about preconditions and postconditions wasn't something new though I never really knew that there was such thing as indicating a postcondition. Is this written in the code? Or is it just to give the programmer a way of assessing whether what they were trying to program was actually successful as accomplishing its task. Nick briefly spoke about crashing programs and how we would perhaps, get the chance to learn that at some point in our undergraduate years. That should be interesting! =)

On another note, Python. When I took CSC148, we were still learning Java so the conversion to Python in most of the lecture material is a lot more difficult. I just took a look at the newest problem set that's due on Monday, and it's all in Python! One of the questions in the assignment is also in Python. I'm going to have to spend a lot of time trying to understand what each command does. =( Hopefully, it won't be much too difficult but I really should get on those assignments. I can't believe there are so many assignments due at the same time from nearly every class!

Pre-Test and Post-Test

Through the process of studying for the test, I've finally managed to figure out what the "unwinding" essentially was. Perhaps, I was too tired and didn't pay as much attention to it in class as I should have. By using this technique, I am able to find a pattern in which to formulate a potential hypothesis for a recursive proof. It works for the example taught in class. I've yet to test it on other proofs of this nature but the concept itself seems clear. Would it work on more complex recursive series? I'll try to find examples to test this out.

The test was as I had expected it to be. Unfortunately, on the last question, I was unable to determine what the value of k was, in the n>k question. In fact, in an attempt to find the value of k, I evaluated various natural numbers and plugged them back into the equation to find a number that would satisfy the equation. I went up to 5, thinking that we wouldn't have been required to go too far. If I had only gone one step further, I would have had the correct value of k. It was a mistake that I know I could have avoided had I have observed the pattern of the other values I was getting. Perhaps, if there was just a few more minutes, I would have gotten to it. Overall, I thought that the test was fair but I could have been more prepared.

Preparing For Test 1

So, the first test is just a few days away and I'm reviewing my notes and trying to reiterate the proofs and concepts that were taught in class. What I find slightly confusing is the material that we covered in the past several lectures that involves unwinding zpf's. Personally, I never was a big fan of recursion despite that fact that it makes things a lot easier. I find it sometimes difficult to think recursively and then apply it towards a logic proof.

This past lecture we were introduced to "Define sets with Induction" and were told that it might be confusing. It was very confusing to me! This is yet another area I will need to focus my time on when preparing for the upcoming test. Given that the test will only be 50minutes, I'm speculating that it would contain several large proofs of some sort using the techniques that we were taught. I'm really hoping that there isn't anything complex or things that i've only recently are beginning to learn.

In any case, I hope it goes well.