Slots

We define a set of family relationships. Some are gender-specific specializations of others. Some can be deduced from combinations of the others.

  (tell '((:slot child    (people people))
          (:slot son      (people people))
          (:slot daughter (people people))

          (:slot parent (people people)  :cardinality 2   :inverse child)
          (:slot father (people people)  :cardinality 1)
          (:slot mother (people people)  :cardinality 1)

          (:slot sibling (people people)  :inverse sibling)
          (:slot brother (people people))
          (:slot sister  (people people))

          (:slot grandchild   (people people))
          (:slot grandson     (people people))
          (:slot grandaughter (people people))

          (:slot grandparent (people people)  :cardinality 4  :inverse grandchild)
          (:slot grandfather (people people)  :cardinality 2)
          (:slot grandmother (people people)  :cardinality 2)

          (:slot uncle (people people))
          (:slot aunt  (people people))))