clique.clj

gistfile1.clj

;; http://dosync.posterous.com/know-your-bounds

(defrel connected ^:index x ^:index y)
(facts connected [[1 2] [1 5]])
(facts connected [[2 1] [2 3] [2 5]])
(facts connected [[3 2] [3 4]])
(facts connected [[4 3] [4 5] [4 6]])
(facts connected [[5 1] [5 2] [5 4]])
(facts connected [[6 4]])

(defne connected-to-allo
  "Ensure that vertex v is connected to all vertices
   vs."
  [v vs]
  ([_ ()])
  ([_ [vh . vr]]
     (connected v vh)
     (connected-to-allo v vr)))

(defne all-connected-to-allo
  "Collect all cliques in l. l must be bounded to ensure
   termination."
  [l]
  ([()])
  ([[h . t]]
     (connected-to-allo h t)
     (all-connected-to-allo t)))

;; ----

(run-nc* [q]
  (fresh [a b d]
    (== q (llist a b d))
    (bounded-listo q 6)
    (all-connected-to-allo q)))
;; => ((2 1) (3 2) ... (5 2 1))