anchor.diff:          // Call the recursive implementation.
           tryFindImpl (predicate, list)
   
  -    //
  +    /// Async implementation of List.find.
       [<CompiledName("Find")>]
       let find (predicate : 'T -> Async<bool>) (list : 'T list) : Async<'T> =
           // Preconditions
  
positive.code:                 return! chooseImpl (chooser, result :: chosen, pending)
          }
  
      //
      [<CompiledName("Choose")>]
      let choose (chooser : 'T -> Async<'U option>) (list : 'T list) : Async<'U list> =
          // Preconditions
  
negative.code:             return! iteriImpl (action, pending, index + 1)
          }
  
      /// Async implementation of List.iteri.
      [<CompiledName("IterateIndexed")>]
      let iteri (action : int -> 'T -> Async<unit>) (list : 'T list) : Async<unit> =
          // Preconditions
  