anchor.diff:       primitive_steps = add_steps built_in_primitive_steps (retrieve_plugins () @ psteps);
        strong = false;
        memoize_lazy = true;
  -     normalize_pure_lets = 
  +     normalize_pure_lets =
          (Options.normalize_pure_terms_for_extraction()
           || not (s |> BU.for_some (eq_step PureSubtermsWithinComputations)));
        reifying = false}
  
positive.code:     let interp_prop_eq3 (psc:psc) _norm_cb (args:args) : option<term> =
          let r = psc.psc_range in
          match args with
          | [(t1, _); (t2, _); (a1, _); (a2, _)] ->    //eq3       
              (match U.eq_inj (U.eq_tm t1 t2) (U.eq_tm a1 a2) with
              | U.Equal -> Some ({U.t_true with pos=r})
              | U.NotEqual -> Some ({U.t_false with pos=r})
  
negative.code:     else snd plugins ()
  
  let add_nbe s = // ZP : Turns nbe flag on, to be used as the default norm strategy
      if Options.use_nbe ()
      then { s with nbe_step = true }
      else s
  
  