Goal

 "2 : the end toward which effort is directed "

Goals are activated by the Agenda, which see.  A Goal contains a Plan which is a list of Tasks though most Plans contain only a single Task.  If the Plan contains more than one Task, each of those Tasks, except for the first, is expected to be dependent on the previous Task in the Plan.  I.e. the Tasks in a Plan are sorted in order of Task dependency.  The final Task in a Plan may or may not be non-simple but any and all preceding task(s) must be simple.

A Goal also maintains a reference to its parent Goal, the realization of which spawned it as a sub-Goal.

A Goal is responsible for cleaning up the agenda if one of its spawned sub-Goals cannot be realized.