(defclass A (is-a USER) (multislot sa))
(defclass B (is-a USER) (slot sb))
(defclass C (is-a USER) (multislot sc))
(defclass D (is-a USER) (slot sd))
(defclass E (is-a USER) (multislot se))
(defclass F (is-a USER) (slot sf))
(defclass G (is-a USER) (multislot sg))
(defclass H (is-a USER) (slot sh))