anchor.diff:  let use_native_tactics           () = get_use_native_tactics          ()
   let use_tactics                  () = get_use_tactics                 ()
   let using_facts_from             () =
  -    let parse_one_setting s =
  -        if s = "*" then ([], true)
  -        else if FStar.Util.starts_with s "-"
  -        then let path = FStar.Ident.path_of_text (FStar.Util.substring_from s 1) in
  -             (path, false)
  -        else let s = if FStar.Util.starts_with s "+"
  -                     then FStar.Util.substring_from s 1
  -                     else s in
  -             (FStar.Ident.path_of_text s, true)
  -    in
  -    let parse_setting s = FStar.Util.split s " " |> List.map parse_one_setting in
       match get_using_facts_from () with
       | None -> [ [], true ] //if not set, then retain all facts
       | Some ns -> List.collect parse_setting ns |> List.rev
  
positive.code:         "Solve all type-inference constraints eagerly; more efficient but at the cost of generality");
  
         ( noshort,
          "extract_module",
          Accumulated (PostProcessed (pp_lowercase, (SimpleStr "module_name"))),
          "Only extract the specified modules (instead of the possibly-partial dependency graph)");
  
negative.code:       ("dump_module"                  , List []);
        ("eager_inference"              , Bool false);
        ("expose_interfaces"            , Bool false);
        ("extract"                      , Unset);
        ("extract_all"                  , Bool false);
        ("extract_module"               , List []);
        ("extract_namespace"            , List []);
  