anchor.diff:      | CheckNoUvars ->  { fs with check_no_uvars = true }
       | Unmeta ->  { fs with unmeta = true }
       | Unascribe ->  { fs with unascribe = true }
  -    in
  -    List.fold_right add_one s default_steps
  +
  +let rec to_fsteps (s : list<step>) : fsteps =
  +    List.fold_right fstep_add_one s default_steps
   
   type psc = {
       psc_range:FStar.Range.range;
  
positive.code:     weak : bool;
      hnf  : bool;
      primops : bool;
      eager_unfolding : bool;
      inlining : bool;
      no_delta_steps : bool;
      unfold_until : option<S.delta_depth>;
      unfold_only : option<list<I.lid>>;
  
negative.code:     weak = false;
      hnf  = false;
      primops = false;
      no_delta_steps = false;
      unfold_until = None;
      unfold_only = None;
  