anchor.diff:  
       // Verify function input form and human form match.
       let convertedForm = NHol.lib.explode externalForm
  -//    printfn "convertedForm: %A" convertedForm
  +//    printfn "external form: %A" externalForm
  +//    printfn "internal form: %A" internalForm
  +//    printfn "converted form: %A" convertedForm
       Assert.AreEqual(convertedForm, internalForm)
   
       // Verify result of function
       let seperatorParser = a seperator
       let stringParser = NHol.parser.listof valueParser seperatorParser "listof error"
       let (current, rest) = stringParser internalForm
  -//    printfn "current: %A" current
  -//    printfn "rest: %A" rest
  +//    printfn "expected result: %A %A" currentResult restResult
  +//    printfn "function result: %A %A" current rest
       Assert.AreEqual(current, currentResult)
       Assert.AreEqual(rest, restResult)
   
  
positive.code: 
  [<Test>]
  [<TestCase(0, TestName = "parser.lex.01")>]
  let ``function lex`` idx =
      let (input, _) = lexValues.[idx]
      let (_, result) = lexValues.[idx]
  
      let strings = NHol.lib.explode input
      let lexResult = NHol.parser.lex strings
      printfn "%A" lexResult
      lexResult |> assertEqual result
  
  (* parse_pretype  tests *)
  
  (* install_parser  tests *)
  
  (* xyzdelete_parser  tests *)
  
  (* installed_parsers  tests *)
  
  
negative.code:     | Ident y when isNum y ->
  //        printfn "x: %A is lexcode num." x
          true
      | _ ->
  //        printfn "x: %A is NOT lexcode num." x
          false
  
  