## 5 – Regression vs Progression

Let’s show an example of where a backwards search makes sense. I’m going to describe a world in which there’s one action, the action of buying a book, and the precondition is we have to know which book it is and let’s identify them by ISBN number. We can buy ISBN number b, and the … Read more

## 4 – Regression Search

Another way to search is called backwards or regression search, in which we start at the goal. So we take the description of the goal state, C1 is at JFK and C2 is at SFO. So that’s the goal state. And notice that that’s the complete goal state. It’s not that I left out all … Read more

## 3 – Progression Search

So the simplest way to do planning is really the exact same way that we did it in problem solving. That we start off in initial state, so P1 was at SFO, say, and cargo C1 was also at SFO. And all the other things that were in that initial state, and then we start … Read more

## 2 – Classical Planning 2

And here we see a more complete representation of a problem solving domain in the language of classical planning. And here’s the Fly action schema, I made it a little bit more explicit with from and to airports rather than x or y. And we want to deal with transporting cargo. So in addition to … Read more

## 1 – Classical Planning-01

Now I want to describe a notation which we call classical planning which is a representation language for dealing with states and actions and plans. And it’s also an approach for dealing with the problem of complexity by factoring the world into variables. So under classical planning the state space consists of all the possible … Read more