anchor.diff:              // Call the recursive implementation function. 
               mapRec (list1, list2)
   
  -    /// The standard F# Seq module, lifted into the Either monad.
  +    /// The standard F# Seq module, lifted into the Choice monad.
       [<RequireQualifiedAccess; CompilationRepresentation(CompilationRepresentationFlags.ModuleSuffix)>]
       module Seq =
           //
  
positive.code: 
  //
  [<RequireQualifiedAccess; CompilationRepresentation(CompilationRepresentationFlags.ModuleSuffix)>]
  module internal Either =
      /// The standard F# Array module, lifted into the Either monad.
      [<RequireQualifiedAccess; CompilationRepresentation(CompilationRepresentationFlags.ModuleSuffix)>]
      module Array =
          //
  
negative.code:             // Preconditions
              checkNonNull "array" array
  
              async {
  
  
  
              raise <| System.NotImplementedException "ExtCore.Control.Collections.Async.Array.map"
              return Array.empty
              }
  
          //
          [<CompiledName("MapIndexed")>]
  