anchor.diff:                            FileMode.Create, 
                             FileAccess.ReadWrite)
   
  -//let input = new StreamReader(``pride and prejudice``)
  -let input = new StreamReader(test)
  +let input = new StreamReader(``pride and prejudice``)
  +//let input = new StreamReader(test)
   let next  = input.ReadLine
   let (|IsAlnum|_|) c = if System.Char.IsLetterOrDigit c then Some () else None
   let (|Int|) input = System.Int32.Parse input
  
positive.code: 
          if len > 0 then yield line.Substring(startIdx, len)
      }
      |> Seq.filter (fun x -> x.Length >= 2 && stopWords.Contains x |> not)
  
  let write (stream : Stream) word count = 
      use writer = new StreamWriter(stream, System.Text.Encoding.ASCII, 128, true)
      writer.WriteLine(sprintf "%s,%d" word count)
      writer.Flush()
  
  let incrFreq (word : string) =
      wordFreqs.Seek(0L, SeekOrigin.Begin) |> ignore
      use reader = new StreamReader(wordFreqs, System.Text.Encoding.ASCII, false, 128, true)
  
  
negative.code:         | null -> false // end of file, word not found
          | line -> 
              let [| word'; (Int count) |] = line.Split(',')
              let lineLen = int64 line.Length + 1L // +1 for newline
              readPosition <- readPosition + lineLen
              if word' = word then
                  wordFreqs.Seek(readPosition - lineLen, SeekOrigin.Begin) |> ignore
                  write wordFreqs word' (count + 1)
                  true
              else
                  loop <| reader.ReadLine()
  
      let found = loop <| reader.ReadLine()
      if not found then write wordFreqs word 1
  