anchor.diff:    receive
       {From, {append, Line}} ->
         From ! {self(), ok},
  -      fileed(Lines ++ [Line], Cursor + 1);
  +      {A, B} = lists:split(Cursor, Lines),
  +      fileed(A ++ [Line] ++ B, Cursor + 1);
       {From, {pop, _}} ->
         From ! {self(), ok},
         fileed(lists:sublist(Lines, length(Lines)-1), Cursor);
  
positive.code:   Pid ! {self(), {append, Line}},
    receive
      {Pid, Msg} -> Msg
    after 3000 ->
      timeout
    end.
  
  append(Pid) ->
  
negative.code:       From ! {self(), {Lines, Cursor}},
        fileed(Lines, Cursor);
      {From, {print, _}} ->
        From ! {self(), lists:nth(Cursor, Lines)},
        fileed(Lines, Cursor);
      {From, {lineCount, _}} ->
        From ! {self(), length(Lines)},
        fileed(Lines, Cursor);
      {From, {setLineNumber, Num}} ->
        From ! {self(), ok},
        fileed(Lines, Num);
      terminate ->
        ok
    end.
  
  