anchor.diff:      | Open lid ->
           record_open false lid
       | ModuleAbbrev (ident, lid) ->
  -        add_dep (lowercase_join_longident lid true);
  +        add_dep deps (PreferInterface (lowercase_join_longident lid true));
           record_module_alias ident lid
       | TopLevelLet (_, patterms) ->
           List.iter (fun (pat, t) -> collect_pattern pat; collect_term t) patterms
  
positive.code:     | [] -> ()
      | _ ->
        let module_name = Ident.lid_of_ids lid.ns in
        match add_dependence_edge module_name with
        | None -> ()
        | Some key ->
          if Options.debug_any () then
              FStar.Errors.warn (range_of_lid lid)
                  (BU.format1 "Unbound module reference %s"
                                  (Ident.string_of_lid module_name))
  
negative.code:   (* Util.print2 "Deps for %s: %s\n" filename (String.concat " " (!deps)); *)
    !deps, !mo_roots
  
  (** Collect the dependencies for a list of given files. *)
  let collect (verify_mode: verify_mode) (filenames: list<file_name>)
      : list<file_name>
      * dependence_graph
      =
    (* The dependency graph; keys are lowercased module names, values = list of
     * lowercased module names this file depends on. *)
    let dep_graph : dependence_graph = smap_create 41 in
  
  
    (* A bitmap that ensures every --verify_module X was matched by an existing X
     * in our dependency graph. *)
  