Planning Domain Description Language (PDDL)

Planning Domain Description Language (PDDL) is a language which is defined by planning community to standardize planning domains. This language developed by [Ghallab et al.] to provide a standard language for 1998/2000 International Planning Competitions.

PDDL consists of two main parts: domain and problem definition. Domain description contanis predicates and operators. Problem description contains the initial and goal states for the domani which it is related to.

The format of a (simple) domain definition is:

 (define (domain DOMAIN_NAME)
 (:requirements [:strips] [:equality] [:typing] [:adl])
 (:predicates (PREDICATE_1_NAME [?A1 ?A2 ... ?AN])
              (PREDICATE_2_NAME [?A1 ?A2 ... ?AN])
 (:action ACTION_1_NAME
   [:parameters (?P1 ?P2 ... ?PN)]
   [:precondition PRECOND_FORMULA]
   [:effect EFFECT_FORMULA]
  )
 (:action ACTION_2_NAME

The format of a (simple) problem definition is:

(define (problem PROBLEM_NAME)

 (:domain DOMAIN_NAME)
 (:objects OBJ1 OBJ2 ... OBJ_N)
 (:init ATOM1 ATOM2 ... ATOM_N)
 (:goal CONDITION_FORMULA)
 )