nc-match-no-override.clj

(defn is-in-env?
  "Return true if node N is in the desired environment according to the
  subtree rooted at G. The following helpers are used:
    (good? g)      - true if g sets the environment to the desired one
    (bad? g)       - (not (good? g)) Note that this includes groups that do
                     not set the environment at all
    (matches? n g) - true if the node N matches G's rule
    (children g)   - a list of G's child groups
    
    Ignores environment trumps/override"
  [n g]
  (and
   (matches? n g)
   (cond
     (good? g) (and
                (for [c (children g)]
                  (or (not (matches? n c)) (is-in-env? n c))))
     (bad? g)  (or
                (for [c (children g)]
                  (and (matches? n c) (is-in-env? n c)))))))

nc-match-with-trump.clj

(defn is-in-env-by-trump?
  "Return true if node N is in the desired environment according to the
  subtree rooted at G because of the environment_trumps flag. The following
  helpers are used:
    (good? g)      - true if g sets the environment to the desired one
    (bad? g)       - (not (good? g)) Note that this includes groups that do
                     not set the environment at all
    (trump? g)     - true if G sets environment_trumps
    (matches? n g) - true if the node N matches G's rule
    (children g)   - a list of G's child groups"
  [n g]
  (and
   (matches? n g)
   (cond
     (not (trump? g))           (or
                                 (for [c (children g)]
                                   (and (matches? n c)
                                        (is-in-env-by-trump? n c))))
     (and (trump? g) (good? g)) (and
                                 (for [c (children g)]
                                   (or (not (matches? n c))
                                       (is-in-env-by-trump? n c))))
     (and (trump? g) (bad? g))  (or
                                 (for [c (children g)]
                                   (and (matches? n c)
                                        (is-in-env-by-trump? n c)))))))