Martin Geisler Online

Yesterday was a rather long day — or to put it more precisely, it became a long day, when Manitou (Jérémy) and I decided to attend a lecture about Models and Logic (the course is called dModLog at DAIMI). We had started our day at 8 O’clock and was finished five hours later. But then we decided to go to the lecture — it lasted for another three hours.

The lecture was really interesting, we heard about Finite Automata, which I believe is also called Finite State Machines. We heard about languages and how to define a Finite Automata in terms of five parameters: Q, Σ, δ, q₀, and F:

• Q is a finite set of states. The states are the memory of the machine, and in any given moment, the machine will be in exactly one of the states.

• Σ is a finite input alphabet. It could be binary digits, the ASCII characters or another finite set of symbols.

• δ is a transition function δ: Q×Σ → Q. δ is the function that makes the machine act on it’s input.

• q₀ ∈ Q is the start state of the machine, and

• F ⊆ Q is the set of final, accepting states. If the machine is in a state in F, then it will answer “Yes”, if not, then it will answer “No”.

You can take a look at the slides that were used if you want to know more. I hope to be able to follow the lectures loosly, as they’re going to prove Gödel’s incompleteness theorem later. Ever since I first heard about it, I’ve wanted to understand what it really says — I’ve only heard the informal explaination of it, namely that it says, that there are things in every closed system that cannot be proved, although they’re known to be true. That sounds like a very fundamental theorem, and I’m really looking forward to learning about it — if not this year, then definitely next year, where dModLog will be part of our mandatory courses.

It’s expensive to live — I’ve just paid a total of 1,800 DKK (about 225 USD) in bills. And one of the bills was to Netsite, so that Gimpster.com can remain online for the next six months.

And then I’ve also bought books for the new term that has just begun. The most exciting new class is the one about algorithms and datastructures. It’s much more advanced than the introduction to Java we were presented with when we started last summer, and the book looks good too. The book is Algorithm Design — Foundations, Analysis, and Internet Examples by Michael Goodrich and Roberto Tamassia. It says in the introduction that it’s typeset with LaTeX so it can’t be all bad ;-) Although I think they’ve made the margins a bit to narrow, especially the right margin on the even pages (the pages that are to the right). But well… that’s how it goes when people insist on changing the standard layout LaTeX produces.

I had my first day at DAIMI today after the reading-holidays. I finished my exams about 14 days ago, so I haven’t been studying that much lately :-) But that didn’t seam to effect our lecturer — he just continued where he had stopped before Christmas.

It’s a little strange that we start on a Friday — I only found out about it yesterday. I thought we could wait until Monday, but no… So I was at the University this morning at 9 O’clock, where I found Manitou (Jérémy). But we were the only two that turned up — even our instructor did come! It was only around 12 O’clock that people started to arrive for the lecture. Two hours later we were finished, and wanted to have a piece of cake from MatKant. But they closed just before we came! So, as you can tell, it’s been a rough day :-)