anchor.diff:              else async.Return Seq.empty
           return! loop () }
   
  -    static member inline Traverse (t: ^a   , f, [<Optional>]_output: 'R, [<Optional>]_impl: Default1) = (^a : (static member Traverse : _*_ -> 'R) t, f)
  +    static member inline Traverse (t: ^a   , f, [<Optional>]_output: 'R, [<Optional>]_impl: Default1) = Traverse.InvokeOnInstance f t : 'R
       static member inline Traverse (_: ^a when ^a : null and ^a :struct, _, _: 'R   , _impl: Default1) = id
   
       static member        Traverse (t: Id<'t>   , f: 't->option<'u>, [<Optional>]_output: option<Id<'u>>, [<Optional>]_impl: Traverse) = Option.map Id.create (f (Id.run t))
  
positive.code: 
  open System.Runtime.CompilerServices
  open System.Runtime.InteropServices
  open FSharpPlus.Internals
  open FSharpPlus.Internals.Prelude
  open FSharpPlus.Internals.MonadOps
  open FSharpPlus
  
  
  type Traverse =
      inherit Default1
      static member inline Traverse (t: ^a   , f, [<Optional>]_output: 'R, [<Optional>]_impl: Default4) = Map.Invoke f (^a : (static member Sequence: _ -> 'R) t)
      static member inline Traverse (t: Id<_>, f, [<Optional>]_output: 'R, [<Optional>]_impl: Default3) = Map.Invoke Id.create (f (Id.run t))
      static member inline Traverse (t: _ seq, f, [<Optional>]_output: 'R, [<Optional>]_impl: Default3) =
         let cons x y = seq {yield x; yield! y}
  
negative.code:         call (Unchecked.defaultof<Traverse>, t, f)
      
  
  type Sequence with
  
      static member inline Sequence (t:_ seq         , [<Optional>]_output: 'R, [<Optional>]_impl:Default4 ) : 'R =
                          let cons x y = seq {yield x; yield! y}
  