anchor.diff:  %%
   %% @doc Delete the specified postings in the index. Postings are a
   %%      6-tuple of the form {Index, Field, Term, Value, Properties,
  -%%      Timestamp}. 
  +%%      Timestamp}.
   delete(State, Postings) ->
       Pid = State#state.pid,
       %% Merge_index deletes a posting when you send it into the system
  
positive.code:                   [{range, Field, [StartTerm, EndTerm]}] ->
                        merge_index:range_sync(Pid, Index, Field, StartTerm, EndTerm, ?SIZE, FilterFun);
  
                    _ -> 
                        {error, {unknown_query_element, Query}}
                end,
      
      %% If Results is a list of results, then call SKFun to accumulate
      %% the results.
      Results1 = case is_list(Results) of
  
negative.code:     merge_index:index(Pid, Postings1).
  
  
  %% @spec lookup_sync(State :: state(), Index::term(), Field::term(), Term::term()) ->
  %%           [{Value::term(), Props::term()}].
  %%
  %% @doc Return a list of matching values stored under the provided
  