The specification of when a State-Of-Affairs must be true in a Planning-Constraint
(Inherited-Facet-Value Slot-Value-Type Effect When-Hold Effect-When-Hold) (Inherited-Facet-Value Slot-Cardinality Effect When-Hold 1) (Inherited-Facet-Value Slot-Value-Type Pre-Condition When-Hold Pre-Condition-When-Hold) (Inherited-Facet-Value Slot-Cardinality Pre-Condition When-Hold 1) (Inherited-Facet-Value Slot-Value-Type Planning-Constraint When-Hold When-Hold-Spec)