;;; ======================================================================
;;;		APIs to KANAL
;;;           
;;;            Jihie Kim   7/30/01
;;; ======================================================================

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;; event structure
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o get-parent-events (event-instance)
  return value: set of events

o get-next-events (event-instance)
  return value: set of events
  NOTE: If there are multiple next events we assume they are conjunctive.
 
o get-prev-events (event-instance)
  return value: set of events

o get-subevents (event-instance)
  return value: set of events

o get-first-subevents (event-instance)
  return value: set of events

;o get-disjunctive-next-events (event-instance)
;  return value: set of events
  NOTE: We are planning to support disjunctive branches in year 2 (2002).

;o get-all-events-involved (process)
;  return value: set of events
  NOTE: This function should return all the events used for describing 
        the process model.
        We are planning to use them to find any unlinked/dangling events.
 
o execute-step (event-instance)
  return value: nil
  NOTE: If there is no simulation function, KANAL can use a dummy function
        and still perform static checks.


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;; preconditions & effects
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o get-preconditions (event-instance)
  return value: the preconditions of the event
 
o get-deletions (event-instance)
  return value: the deleted effects

o get-assertions (event-instance)
  return value: the added effects

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;;  expressions
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o equal-objects (obj1 obj2)
  return value: true/false

;; test if the expr is true or false
o test-expr (expr &optional (situation nil)) 
  return value: true/false


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;; concepts/roles/instances
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o get-role-values (instance role)
  return value: the role value of the instance
  EXAMPLE: (the color of the roof --> Red)

o create-instance (concept &optional (situation nil))
  return value: an instance

o get-inverse (role)
  return value: the inverse of role

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;; to handle situation
;;
;; NOTE: KANAL needs these only if the KBS support situations and the
;;       simulation done based on the situations (e.g., KM)
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o goto (situation-instance)
  return value: the situation

o goto-global-situation ()
  return value: the global situation

o create-situation ()
  return value: the new situation

o current-situation ()
  return value: the current situation

o previous-situation (situation-instance)
  return value: the previous situation

o get-after-situation (event-instance)
  return value: the after situation


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;; for proposing fixes
;;
;; NOTE: KANAL needs these only if you want 'proposed fixes from KANAL',
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o assert-role-value (instance role val)
  return value: nil

o get-concepts-from-instance (instance)
  return value: the classes the instance belongs

o get-subclasses (class)
  retun value: classes

o get-superclasses (class)
  return value: classes

o isa-class (obj class)
  return value: true/false

o get-concept-action ()
  return value: the class Action/Event
  NOTE: the root of all the event classes

;o get-all-subclasses (class)
;  retun value: classes
   NOTE: optional

;o get-all-superclasses (class)
;  return value: classes
   NOTE: optional

o evaluate-expr (expr)
  return value: the result of the evaluation