include "ground/lib/list_rcons.ma".
include "ground/notation/functions/element_e_0.ma".
include "ground/notation/functions/black_circle_2.ma".
+include "ground/notation/functions/black_halfcircleright_2.ma".
+include "ground/notation/functions/black_halfcircleleft_2.ma".
include "delayed_updating/syntax/label.ma".
-include "delayed_updating/notation/functions/black_halfcircleright_2.ma".
-include "delayed_updating/notation/functions/black_halfcircleleft_2.ma".
(* PATH *********************************************************************)
+(* Note: a path is a list of labels *)
definition path ≝ list label.
interpretation