anchor.diff:  open System
   open System.Collections.Generic
   open Models
  -open Points
   open ValidationResult
   
   let drawNumbers () =
  
positive.code:         let (ErrorMessage m1, ErrorMessage m2) = e1, e2
          m1 + m2 |> ErrorMessage |> Error
      | Success usersDraw, Success (extraNumber, drawResultWithoutExtraNumber) -> 
          let points = 
              (Set.ofList usersDraw, Set.ofList drawResultWithoutExtraNumber)
              ||> Set.intersect
              |> Set.count
              |> (decimal >> Points)
  
          let extraPoints = 
              match List.tryFind ((=) extraNumber) usersDraw with
              | Some _ -> Points 0.5m
              | None -> Points 0.m
  
          points .+. extraPoints |> Prize.fromPoints |> ValidationResult.success
  
negative.code:         >=> splitDrawResults
          >=> validateOneExtraNumbersWithSixDrawnumbers
  
      let calculatePoints usersDraw (drawResultWithoutExtraNumber, extraNumber) =
          let points = 
              (Set.ofList usersDraw, Set.ofList drawResultWithoutExtraNumber)
              ||> Set.intersect
              |> Set.count
              |> decimal
  
          let extraPoints = 
              match List.tryFind ((=) extraNumber) usersDraw with
              | Some _ -> 0.5m
              | None -> 0.m
  
          points + extraPoints |> Points
  
      let drawResultsValidated, usersDrawValidated =
          drawResults |> validateDrawResults,
          usersDraw |> validateUsersDraw
  