A PLAN is a SPECIFICATION of ACTIVITY to meet one or more OBJECTIVES.
A SPECIFICATION of ACTIVITY denotes or describes one or more ACTIVITIES.
An ACTIVITY may change the STATES-OF-AFFAIRS.
STATES-OF-AFFAIRS is something that can be evaluated as holding or not.
An AGENT can perform ACTIVITIES and/or hold OBJECTIVES.
An OBJECTIVE may have one or more EVALUATION-CRITERIA.
An EVALUATION-CRITERIA is an ASPECT of [past, present or possible future] STATES-OF-AFFAIRS or an ASPECT of [one or more] PLANS.
An EVALUATION is a predicate (holds/does not hold) or a preference ranking on EVALUATION-CRITERIA.
An ACTIVITY takes place over a TIME-INTERVAL identified by its two ends, the BEGIN-TIME-POINT and the END-TIME-POINT. The BEGIN-TIME-POINT is temporally before the END-TIME-POINT.
An ACTIVITY-SPECIFICATION may have ACTIVITY-CONSTRAINTS associated with it and its TIME-INTERVAL.
An ACTIVITY-SPECIFICATION may include one or more SUB-ACTIVITIES.
SUB-ACTIVITY: Sub-activities are the constituent activities designated in any ACTIVITY-SPECIFICATION.
PRIMITIVE ACTIVITY is an ACTIVITY whose ACTIVITY-SPECIFICATION contains no (further) ACTIVITIES.
ACTIVITY CONSTRAINTS can be stated with respect to none, one or more than one time point. They express things which are required to hold They are evaluable with respect to a specific PLAN as holding or not holding.