anchor.diff:        let y = fib (n-1L)
         x.Result + y
   
  -  let run () =
  +  let run n =
       printf "ParTsk: "
       let timer = Stopwatch.StartNew ()
       let r = fib n
  
positive.code:       fib (n-2L) <*> fib (n-1L) |>> fun (x, y) ->
        x + y
  
    let run () =
      printf "ParOpt: "
      let timer = Stopwatch.StartNew ()
      let r = run (fib n)
  
negative.code:       return x + y
    }
  
    let run n =
      printf "ParJob: "
      let timer = Stopwatch.StartNew ()
      let r = run (fib n)
  