gistfile1.clj

(defrel person id)
(defrel task id start end duration)

(facts person [['A] ['B]])
(facts task [[1 0 10 5]
             [2 0 10 9]
             [3 0 11 3]])

(defne personso [q]
  ([()])
  ([[[_ p _ _] . r]]
    (person p)
    (personso r)))

(defne time-intervalso [q lp]
  ([() _])
  ([[[_ a _ _]] [_ b _ _]] (!= a b))
  ([[[ta a as ae] bv . r] _]
     (matche [bv]
       ([[tb b bs be]]
          (!= a b)
          (time-intervalso r bv)))))

; each data element => [task-id person-id start-time end-time]
(comment
  (let [data [[1 (lvar) (lvar) (lvar)]
              [2 (lvar) (lvar) (lvar)]
              [3 (lvar) (lvar) (lvar)]]]
    (run* [q]
      (== q data)
      (personso q)
      (time-intervalso q (lvar))))
  )