Task durations

[vakker]

Hi,

Does SHOP3 support task durations?
The documentation doesn't mention it:

(:op head
       [:precond precondition]
       [:delete delete-list]
       [:add add-list]
       [:cost cost-fn])

But in the PDDL examples (e.g. IPC-2002/Depots/SimpleTime/stdepots.pddl) there are actions with :duration (= ?duration 10).

PDDL should be strictly less expressive than SHOP3, so I assume there's a way to capture that without PDDL, right?

Thanks

[rpgoldman]

Hi, @vakker -- I'm changing this from an Issue to a Discussion, because I'd like Q&A's to be searchable, but Issues might be harder to find. More to follow.

[vakker]

Makes sense, sorry about that! Thanks for looking into it!

[rpgoldman]

Answering the question now....

[rpgoldman]

SHOP3 does not have temporal planning fully built in. There are a couple of ways to do temporal (sometimes called "durative") planning with SHOP3:

1. There's a method for dealing with it that is described in an early paper on SHOP2 that the folks at University of Maryland figured out. See Section 4.2 in this paper
2. I developed a different technique that is described in this paper. If you are interested in this method, I can dig up the temporal-shop2 system and put it into SHOP3. It will likely need some maintenance to work with SHOP3, but it shouldn't take much.

[vakker]

Thanks, that helps. If you could provide the example temporal-shop2 that would be highly appreciated!

[rpgoldman]

I'm getting it packaged up now. I got bogged down with fixing the Blocks domain, which in turn led me to discover that the GitHub actions were all broken! 🤯

[rpgoldman]

I have published the temporal-shop code to this project: https://github.com/shop-planner/temporal-shop

Note that this code has not been updated to SHOP3 so almost certainly will not work out of the box. I aspire to getting it updated, but don't have any time to dig into it right now. Any updates would be very welcome as pull requests!

[vakker]

Thanks! Is that repo public? That link gives 404 for me.

[rpgoldman]

Sorry! It was meant to be public; I didn't realize it would default to private. Fixed now.