anchor.diff:                         0 ->  [{delete, Path} | Acc];
                          _ ->  [{put, Path, Map2} | Acc]
                        end
  -                     
  +                 end,
  +          merge(Rest, DocId, Op, Fun, St, Acc2);
  +        error ->
  +          Acc2 = case Op of
  +                   add ->
  +                     [{put, Path, #{ Sel => [DocId]}} | Acc];
  +                   del ->
  +                     Acc
                    end,
             merge(Rest, DocId, Op, Fun, St, Acc2)
         end;
  
positive.code:                  [{put, Path, #{ Sel => [DocId]}} | Acc];
                 del ->
                   Acc
      
               end,
        merge(Rest, DocId, Op, Fun, St, Acc2)
    end;
  
negative.code:                        del -> Entries -- [DocId]
                       end,
            Sz = length(Entries2),
            Acc2 = if
                     Sz > 0 ->
                       Map2 = Map#{ Sel => Entries2 },
  