Definition ruleMatchesF
  (s : subject)
  (o : object)
  (a : action)
  (r : rule)
: bool :=
  let sm := exprMatchSubjectEvalF s (rMatchSubject r) in
  let om := exprMatchObjectEvalF o (rMatchObject r) in
  let am := exprMatchActionEvalF a (rMatchAction r) in
    andb (andb sm om) am.
