So, this is the idea.

We write down facts about the world,

easy facts like Socrates is human,

Peter loves Mary,

Zuda is Bavarian.

I don't know this translation.

Okay, these kind of facts about the world,

and we add rules about the world,

something like every human is fallible,

or whatever X you take,

if you add zero to it,

you get X still, and so on.

That's a programming language.

We will see later that we can quite generally

see computation as logic,

which is what this is,

namely a language where we can write down

knowledge about the world and what we call control,

in this case search.

We're going to come back to that when

we've actually understood search better.

Good. So, I've attempted to convince you

that if you write down knowledge about numbers,

you get programming with numbers,

and here you have programming with the Greeks.

Okay. So, depending on what you write your knowledge about,

you get a programming paradigm for that.

Okay. Now, we learn the syntax.

Okay. First, we need to have

a notion of what the building blocks are.

We have constants like Socrates or 3,

or 17, or the string so-and-so.

We have variables, any self-respecting

programming language needs those.

There's nothing new with in Prolog about that,

except of course variables,

you can only write in uppercase.

If you write something, a string,

a name, in uppercase,

it's going to be a variable.

If it's lowercase, it's going to be

a constant or a predicate.

Okay. We have functions of

predicates and they are written lowercase.

Other than that, the usual restrictions apply.

They can't have, they're mostly letters,

and possibly numbers, and underscores,

and that's what you have for making names.

Look at the Prolog specification

if you really want to know what this is.