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Resources

Demo problems

Here you are a set of demo problems for all the tracks. These are the problems from the last IPC 2008. Find the appropriate set of problems for your track:

Be sure your planner works with these domains!

Supporting Tools

We expect to be able to provide a limited set of supporting tools in this section (for a limited set of programming languages).

Syntax Checker

Plan Validator

The Plan Validator to be used in the IPC 2011 is VAL 4.2.09 from the Strathclyde Planning Group

It is mandatory to use at least this version since it is the first one which also acknowledges step length as a metric (flag '-L'). Our copy of VAL 4.2.09 can be downloaded from here.

PDDL Papers

The following subsections provide some pointers to various aspects related to PDDL

IPC 2011

The complete and commented BNF syntax of PDDL 3.1 is available in two unpublished works that Daniel L. Kovacs has kindly sent to the IPC 2011:

While this work contains a complete, final definition of PDDL 3.1, another draft is also available which discusses some imperfections in the original PDDL definitions and their correction.

The first paper introduces an extension of the STRIPS formalism to include functional state variables, which map to objects of the planning problem instead of the set {true, false}. Functional state variables often allow modeling a domain more naturally. The main language extension in PDDL 3.1, object fluents, are modeled after Functional Strips. The SAS+ planning formalism (see second paper) can be seen as a special case.

Besides, a thorough discussion about PDDL 3.1 can be found at Changes in PDDL 3.1 at the Wiki of the IPC 2008 ---from where most contents have been copied and pasted to this one!

These papers describe PDDL 3.0, which extends PDDL 2.2 by trajectory constraints and preferences. A trajectory constraint is a constraint on the set of valid plans; they are expressed in a temporal logic. Preferences allow expressing soft constraints (soft trajectory constraints, soft preconditions and soft goals), which are constraints that need not be satisfied by a plan, but lead to a decrease in plan quality if they are not.

The papers by Edelkamp and Hoffmann introduce PDDL 2.2, which extends PDDL 2.1 by derived predicates (state variables which are computed as a function of other state variables) and by timed initial literals (propositions that are "autonomously" set to true or false at a certain time point in a temporal plan). The papers by Thiébaux et al. provide motivation, formal semantics and analysis of expressivity for derived predicates.

The first paper introduces PDDL 2.1, which extends the version of PDDL used in the previous competitions by numeric state variables and an explicit model of concurrency (durative actions, with either discrete or continuous effects). The second paper further extends PDDL 2.1 into a language called PDDL+, introducing autonomous processes that are triggered either by actions of the planning agent or by effects of other autonomous processes. The other papers are "opinion papers", written as a response to PDDL 2.1.

This paper defines the subset of PDDL that was used for IPC-2 in 2000. Many features of the original PDDL that had not been used at the planning competition were not included (e.g. domain axioms, safety constraints, hierarchical actions, numerical fluents). All further extensions of PDDL add to this subset, rather than the original PDDL.

The paper by McDermott et al. is the original definition of PDDL, as used for IPC-1 in 1998.


2013-10-04 16:47