graph.clj

(comment
  (defrel edge a b)

  (def graph [{:id :gen :in [] :out ["a" "b"]}
              {:id :plus :in ["a"] :out ["plus"]}
              {:id :times :in ["plus"] :out ["times"]}])

  (fact edge '{:id :gen :in [] :out ["a" "b"]} '{:id :plus :in ["a"] :out ["plus"]})
  (fact edge '{:id :plus :in ["a"] :out ["plus"]} '{:id :times in ["plus"] :out ["times"]})

  (defn get-out-fields [x]
    (:out x))

  (defn get-in-fields [x]
    (:in x))

  (defne ancestorso
  "y is all ancestors of x"
  [x y]
  ([x y]
     (edge y x))
  ([x y]
     (fresh [z]
            (edge z x)
            (ancestorso z y))))

  (defne descendantso
  "y is all descendants of x"
  [x y]
  ([x y]
     (edge x y))
  ([x y]
     (fresh [z]
            (edge x z)
            (descendantso z y))))

  (defn siblingso
  "y is all siblings (common parent) of x"
  [x y]
  (fresh [z]
         (edge z x)
         (edge z y)
         (!= x y)))

  (defn common-ancestoro
  "r is all common acenstors of x and y"
  [x y r]
  (ancestorso x r)
  (ancestorso y r))

  (run* [q]
        (siblingso q {:id :plus :in ["a"] :out ["plus"]}))

  )