anchor.diff:      try
           P1 = new_simple_projection(1, 1, 1*100, [[F1, F2], [F3, F4]]),
           [begin {ok, LPN} = append_page(Seq, P1, Pg) end || {LPN, Pg} <- LPN_Pgs],
  +
           [begin {ok, Pg} = read_page(P1, LPN) end || {LPN, Pg} <- LPN_Pgs],
  +
  +        [begin
  +             LPNplus = LPN + 1,
  +             {ok, LPNplus, true, [{LPN, Pg}]} = scan_forward(P1, LPN, 1)
  +         end || {LPN, Pg} <- LPN_Pgs],
  +        {ok, 6, false, []} = scan_forward(P1, 6, 1),
  +        {ok, 6, false, []} = scan_forward(P1, 6, 10),
  +        [{LPN1,Pg1}, {LPN2,Pg2}, {LPN3,Pg3}, {LPN4,Pg4}, {LPN5,Pg5}] = LPN_Pgs,
  +        {ok, 4, true, [{LPN2,Pg2}, {LPN3,Pg3}]} = scan_forward(P1, 2, 2),
  +        {ok, 6, false, [{LPN3,Pg3}, {LPN4,Pg4}, {LPN5,Pg5}]} = scan_forward(P1, 3, 10),
  +
           ok
       after
           corfurl_sequencer:stop(Seq),
  
positive.code:          new_range/3,
           read_projection/2,
           save_projection/2]).
  -export([append_page/3, read_page/2]).
  
  -include("corfurl.hrl").
  
  
negative.code:             error({impossible, ?MODULE, ?LINE, overwritten_reply_to_read});
          error_unwritten ->
              %% TODO: Check head for possible read-repair
              error_unwritten
      end.
  
  scan_forward(P, LPN, MaxPages) ->
      scan_forward(P, LPN, MaxPages, ok, true, []).
  
  scan_forward(_P, LPN, 0, Status, MoreP, Acc) ->
      {Status, LPN, MoreP, lists:reverse(Acc)};
  scan_forward(P, LPN, MaxPages, _Status, _MoreP, Acc) ->
      case read_page(P, LPN) of
          {ok, Page} ->
              Res = {LPN, Page},
              scan_forward(P, LPN + 1, MaxPages - 1, ok, true, [Res|Acc]);
          error_badepoch ->
              %% Halt, allow recursion to create our return value.
              scan_forward(P, LPN, 0, error_badepoch, false, Acc);
          error_trimmed ->
              %% TODO: API question, do we add a 'trimmed' indicator
              %%       in the Acc?  Or should the client assume that if
              %%       scan_forward() doesn't mention a page that
              scan_forward(P, LPN + 1, MaxPages - 1, ok, true, Acc);
          error_overwritten ->
              error({impossible, ?MODULE, ?LINE, overwritten_reply_to_read});
          error_unwritten ->
              %% Halt, allow recursion to create our return value.
              scan_forward(P, LPN, 0, ok, false, Acc)
      end.
  
  flu_pid(X) when is_pid(X) ->
  