plan being immovable while no freeing/reallocating actions are permitted. The domain
of RA i is the range of available resources. Serializing the plan implies that the action of
the plan can move subject to an upper plan length, L MAX , provided by the planner. Again,
no freeing/reallocating actions are permitted to be inserted. An example of L MAX is the
number of actions in the plan, which allows the plan to be completely serialized.
In introducing resource freeing/reallocating actions, we identify three sub-cases. If
actions are considered immovable, this corresponds to Class FIX. Here, the freeing
action can be introduced immediately after A i while the reallocating action (U ij )
can come immediately before A j .
The second sub-case is when the actions are allowed to move up to the length of the
abstract plan, and this corresponds to Class SAMELEN. Finally, the actions are allowed to
move till any upper limit L MAX (L MAX L) in Class INCRLEN.