anchor.diff:  open Fable.Arch.Html
   open Fable.Arch.RouteParser.Parsing
   open Fable.Arch.RouteParser.RouteParser
  +open Fable.Core.JsInterop
   open Fable.Import.Browser
   open System.Text.RegularExpressions
   
  
positive.code:   | Sum (numA, numB) -> Some (sprintf "/sum/%i/%i" numA numB)
    | Sub (numA, numB) -> Some (sprintf "/sub/%i/%i" numA numB)
    | Mul (numA, numB) -> Some (sprintf "/mul/%i/%i" numA numB)
  
  let mapToRoute route =
    match route with
  
negative.code:   open Fable.Core.JsInterop
  
    let onInput x = onEvent "oninput" (fun e -> x (unbox e?target?value))
  
  type Actions =
    | NavigateTo of Page
  