anchor.diff:              >> Option.bind (function | [x] -> Some x | _ -> None)
               >> Option.bind f
   
  -        let assignIndexedElements magicCode f length =
  +        let getIndexedElements magicCode f length =
               let impl opt entries =
                   match opt, entries with
                   | Some array, UInt16 index :: xs -> maybe {
  
positive.code: 
          let readGroup fSymbol fGroup index =
              let readNestedGroups =
                  (function | UInt16 x :: xs -> x |> fGroup |> Option.map (fun x -> x, xs) | _ -> None)
                  |> readToEnd true
                  >> Option.map set
              function
              | String name :: UInt16 containerIndex :: UInt16 startIndex :: UInt16 endIndex :: UInt16 advanceMode :: UInt16 endingMode :: Empty :: UInt16 _nestingCount :: xs -> maybe {
  
negative.code:         let readDFAState fCharSet fSymbol fDFA index =
              let readDFAEdges =
                  function
                  | [UInt16 charSetIndex; UInt16 targetIndex; Empty] -> maybe {
                      let! charSet = fCharSet charSetIndex
                      let! target = fDFA targetIndex
                      return (charSet, target)
                      }
                  | _ -> None
                  |> readToEnd false 3
              function
              | Boolean false :: UInt16 _ :: Empty :: xs ->
                  xs
  