anchor.diff:  
       [<Property>]
       let ``Fun pattern works``(Fun (f:bool->bool)) =
  -        let a = f true
  -        let b = f false
  +        let _ = f true
  +        let _ = f false
           true =! true
   
       [<Property>]
  
positive.code:     let ``Map with string key``() =
          generate<Map<string, char>> |> sample 10 |> List.exists (fun x -> not x.IsEmpty)
  
      [<Property>]
      let Decimal() =
          generate<decimal> |> sample 10 |> List.forall (fun _ -> true)
  
      [<Property>]
      let ``Decimal shrinks`` (value: decimal) =
          shrink<decimal> value 
          |> Seq.forall (fun shrunkv -> shrunkv = 0m || shrunkv <= abs value)
  
      [<Property>]
      let Culture() =
          generate<CultureInfo> |> sample 10 |> List.forall (fun _ -> true)
  
  //commented out as it keeps failing on AppVeyor with: ca-ES-valencia, pretty hard to repro.
  //    [<Property>]
  
negative.code:         shrink value 
          |> Seq.forall (fun (KeyValue(k,v)) -> shrink value.Key |> Seq.exists ((=) k) || shrink value.Value |> Seq.exists ((=) v))
  
      [<Property>]
      let ``Array shrinks to shorter array or smaller elements`` (value:int[]) =
          shrink value 
          |> Seq.forall (fun v -> v.Length < value.Length || Array.exists2 (fun e1 e2 -> abs e1 <= abs e2) v value)
  