anchor.diff:  
   let tc_decls env ses =
     let rec process_one_decl (ses, exports, env, hidden) se =
  +    (* If emacs is peeking, and debugging is on, don't do anything,
  +     * otherwise the user will see a bunch of output from typechecking
  +     * definitions that were not yet advanced over. *)
  +    if env.nosynth && Options.debug_any ()
  +    then (ses, exports, env, hidden), []
  +    else begin
       if Env.debug env Options.Low
       then BU.print2 ">>>>>>>>>>>>>>Checking top-level %s decl %s\n"
                           (Print.tag_of_sigelt se)
  
positive.code:  * the list of typechecked sig_elts, and a list of new sig_elts elaborated
   * during typechecking but not yet typechecked *)
  let tc_decl env se: list<sigelt> * list<sigelt> * Env.env =
    (* If emacs is peeking, and debugging is on, don't do anything,
     * otherwise the user will see a bunch of output from typechecking
     * definitions that were not yet advanced over. *)
    if env.nosynth && Options.debug_any ()
    then [], [], env
    else begin
     let env = set_hint_correlator env se in
     if Options.debug_module (string_of_lid env.curmodule) then
       BU.print1 "Processing %s\n" (U.lids_of_sigelt se |> List.map string_of_lid |> String.concat ", ");
  
negative.code:         List.fold_left accum_exports_hidden (exports, hidden) ses'
      in
      (List.rev_append ses' ses, exports, env, hidden), ses_elaborated
      end
    in
    // A wrapper to (maybe) print the time taken for each sigelt
    let process_one_decl_timed acc se =
  