-extern tree lookup_name_nonclass (tree);
-extern tree lookup_function_nonclass (tree, tree);
-extern tree lookup_qualified_name (tree, tree, bool, bool);
-extern tree lookup_name (tree, int);
-extern tree lookup_name_current_level (tree);
-extern tree lookup_type_current_level (tree);
-extern tree lookup_name_real (tree, int, int, int, int);
-extern tree namespace_ancestor (tree, tree);
-extern bool is_ancestor (tree, tree);
-extern tree unqualified_namespace_lookup (tree, int, tree *);