336 Chapter 14 Temporal Planning
An action a = σ (o), for some substitution σ , is a partially instantiated planning
operator o. Since an action a is a chronicle a = (F(a), C(a)), Definition 14.10 (see
page 333) is used directly to specify when an action is applicable and what is its
result.
An action a is applicable to iff supports the chronicle (F(a), C(a)). The result
of applying a to is not a unique chronicle but a set:
γ (, a) ={ ∪ φ | φ ∈ θ (a/)}
An action a is a chronicle, θ (a/), as defined according to Definition 14.11. Hence,
every element of γ (, a) is a consistent chronicle.
A set π ={a
1
, ..., a
n
} of actions is also a chronicle
π
=
i
(F(a
i
), C(a
i
)).
Again, a plan π will be defined as a set, not as a sequence. The general constructs ...