Prolog.KnowledgeBase.CheckForPredicateInfo C# (CSharp) Метод

        internal PredicateInfo CheckForPredicateInfo(PredicateIndicator p)
        {
            PredicateInfo info = CheckForPredicateInfoInThisKB(p);
            if (info != null)
                return info;
            foreach (KnowledgeBase import in imports)
                if ((info = import.CheckForPredicateInfo(p)) != null)
                    return info;
            return null;
        }

        private void WalkGoal(KnowledgeBase kb, KnowledgeBaseRule rule, object goal)
        {
            goal = Term.Deref(goal);
            var atom = goal as Symbol;

            if (atom != null)
            {
                var p = new PredicateIndicator(atom, 0);
                if (PrologPrimitives.IsDefined(p))
                {
                    return;
                }
                var predicate = kb.CheckForPredicateInfo(p);
                if (predicate == null)
                {
                    rule.PrintWarning("undefined predicate {0}", p);
                }
                else
                {
                    MarkReferenced(predicate);
                }
            }
            else
            {
                var s = goal as Structure;
                if (s != null)
                {
                    WalkGoal(kb, rule, s);
                }
                else if (!(goal is LogicVariable) && !(goal is bool))
                {
                    rule.PrintWarning("malformed goal: {0}", goal);
                }
            }
        }