It represents integer.

E goes to E plus E or E goes to int.

Since this one isn't recursive, there are only a finite number of strings in the language

So here's our grammar it has 4 rewrite rules.

INT string and INT alone.

So here the language of our grammar includes things like INT INl, INT INT INT.

Now let's dig into this notion of parcing states a little bit more.

int min minutes

int sec seconds

int alarm minutes before event to send an alarm

Prev

Next

0 Indicates that this event does not recur

1 This event recurs daily

2 This event recurs on a weekly basis

Use DEFAULT 0 instead.

int id ID of that event.

I want to see if this one string could have been produced by our grammar.

However, if we were to add a few more INTs, this trick that I've done here of reducing INT goes to INT goes to INT if I had 1, 2, 3, 4, 5, 6 tokens,

Neither of these rules makes the grammar ambiguous.

This time, I'm going to give you the parse tree, and I want you to tell me what the grammar would have to be.

We saw the integer token, and we were expecting that because one of our parse states here was

So, conceptually, one of the first things we'll do is shift.

So one of our rules is

This is consistent with the world that we've been presented.

Here's a much simpler grammar to try out this concept on.

It fits with our grammar and it's the input token we saw, and next, we'll want to shift over this (int).

And you put from the current state, state 2.

(int int) but we've only seen 2 of those tokens so far the (int) and the (minus).

But here is where the potential ambiguity comes in.

Alright, how about this?

To evaluate this, it starts at the inner parenthesis.

3 7 is 10.

Well, one way to view this is to think about the parse tree, which I've kind of drawn here upside down.

int public TRUE if the event if public, FALSE if it is private.

However, they're not exactly the same.

There is nothing to the past. Everything is to the future.

Starting with E, I choose to apply E goes to E plus E.

string title Title string of the event.

So this is the second state that I could be in.

Let's say one of our current states is E goes to dot int, and we actually see that int.

Then it tries to take the type of 10, which is a type int, then it prints that type int.

One last way to see way to see why we need it.

But now we could also start looking for another int.

Returns an event object consisting of