OK.

I'm guessing you know the usual procedure.

The quiz should start within the next minute, I would hope.

It's supposedly running, is it working?

Huh?

It's frozen, OK.

That's not good.

Is it working now?

Well, that didn't help then.

How about now?

Well, OK. Our engineer is working on it.

So we will try again after the break, which is five-ish, I guess.

Sorry?

OK, then let's just say at five.

Well, that's a pity.

That hasn't happened in a while though.

I wonder what went wrong now.

Anyway, can we do...

This is already off.

Oh.

Doesn't that work?

That seems reasonable, right?

OK.

So as you may have noticed, Professor Kohlhase is not here.

Instead I am.

Yeah, sorry?

Just wait until five.

If it started now, it's not going to be running for long because our engineer is actively debugging things.

So he might kill it any second.

So Professor Kohlhase is not here.

My name is Dennis Müller.

I'm a postdoc in Professor Kohlhase's group.

I'll be taking over for today.

Professor Kohlhase will be back tomorrow morning.

For those of you who don't know me, well, you do now.

And for those of you who intend to take the AI2 lecture next semester, there's a decent chance we'll meet again.

Professor Kohlhase is very likely going to be on a sabbatical next semester, and I'm going to take over the AI2 lecture if that happens.

Just to give you some recap, I think last week you started with the topic of formal logic.

Typically one of those topics that people in the final exam tend to have difficulties with.

So be warned.

It's certainly going to be relevant for the exam, and it's certainly not going to be easy, especially if you don't have any prior knowledge in that area.

If you've taken, like, I don't know, theoretical computer science or something in your undergraduate, you're likely going to be fine.

We're only focusing on propositional logic and first-order logic anyway.

So if you've taken any kind of courses, logic in computer science or one of these kinds of things, you're probably going to be fine.

If not, don't underestimate this. This is going to be a major part of the exam.

Yeah.

By and large, the relevant things in a logic are twofold.

One being the syntax. The syntax tells us simply what a well-formed formula is according to some grammar, and the semantics, which tells us what a formula actually means.

We need both. I'm assuming you're somewhat familiar with the notation by now. You should have done this last week.

Yeah.