;; a small example of clinical knowledge base
;; illustrating the use of right-identity rule in medical application

(define-primitive-role contained-in)
(define-primitive-role part-of :parent contained-in :transitive t)
(define-primitive-role has-location :right-identity contained-in)

(define-primitive-concept Endocardium
    (and Tissue
	 (some contained-in HeartWall)
	 (some contained-in HeartValve)))
(define-primitive-concept HeartWall
    (and BodyWall
	 (some part-of Heart)))
(define-primitive-concept HeartValve
    (and BodyValve
	 (some part-of Heart)))
(define-primitive-concept Endocarditis
    (and Inflammation
	 (some has-location Endocardium)))
(define-primitive-concept Inflammation
    (and Disease
	 (some acts-on Tissue)))

(define-concept Heartdisease
    (and Disease
	 (some has-location Heart)))

(implies (and Heartdisease
              (some has-location HeartValve))
	 CriticalHeartDisease)