anchor.diff:            | None -> [ { se with sigel = Sig_new_effect (ne) } ]
         in
   
  -      [], ses @ effect_and_lift_ses
  +      [], ses @ effect_and_lift_ses, env0
   
     | Sig_new_effect(ne) ->
       let ne =
  
positive.code:         | None ->
              raise_error (Errors.Fatal_SplicedUndef, BU.format2 "Splice declared the name %s but it was not defined.\nThose defined were: %s" (string_of_lid lid) (String.concat ", " <| List.map string_of_lid lids')) r
      ) lids;
      [], ses
  
    | Sig_let(lbs, lids) ->
      let env = Env.set_range env r in
  
negative.code:     in
  
      let uvs, t = tc_assume env (uvs, t) se.sigrng in
      [ { se with sigel = Sig_assume (lid, uvs, t) }], [], env0
  
    | Sig_main(e) ->
      let env = Env.set_range env r in
  