anchor.diff:                      | Eager_unfolding_only -> true
                       | Unfold l -> Common.delta_depth_greater_than f.fv_delta l) in
               let should_delta =
  -                if List.mem Env.UnfoldTac cfg.delta_level &&
  +                if cfg.steps.unfold_tac &&
                      (  S.fv_eq_lid f PC.and_lid
                      || S.fv_eq_lid f PC.or_lid
                      || S.fv_eq_lid f PC.imp_lid
  
positive.code:                                     | Some attrs -> BU.for_some (attr_eq attr) attrs
                                      | None -> true
                                      end)
                    else should_delta
                  end
              in
  
  
negative.code:             //log cfg (fun () -> BU.print "Tm_fvar case 0\n" []) ;
              rebuild cfg env stack t
  
            | Tm_app(hd, args)
              when U.is_fstar_tactics_embed hd
                || (U.is_fstar_tactics_quote hd && cfg.steps.no_delta_steps)
  