anchor.diff:  let mainWithOptions opts = 
       let input = opts.input
       let raw = opts.raw
  +    let optimise = not opts.noOptimise
       
       let starlingR = 
           match (requestFromStage opts.stage) with
  -        | Some otype -> runStarling otype input
  +        | Some otype -> runStarling optimise otype input
           | None -> fail Error.BadStage
       
       let pfn = 
  
positive.code:         >> termGen
          >> reify
          >> flatten
          >> optimise
          >> hsf
          >> lift Response.HSF
  
  
negative.code:                                                 | Lang.Frontend.Response.Model m -> m |> ok
                                                  | _ -> Other "internal error: bad frontend response" |> fail)
  
  /// Runs the Starling request at argument 2 on the file named by argument 3.
  /// If missing, we read from stdin.
  /// Argument 1 turns optimisation on if true.
  let runStarling opt = 
      let maybeOptimise = if opt then optimise else id
  
      function 
      | Request.Frontend rq -> frontend rq >> lift Response.Frontend
      | Request.Destructure -> 
  