message: improve type
diff: @@ -205,7 +205,7 @@ export type MergeA<Ls extends SyncLayer<any, any, any>[]> = UnionToIntersection<
  export type SyncMemoMap = Map<symbol, any>
  export function getMemoOrElseCreate<R, E, A>(layer: SyncLayer<R, E, A>) {
  - return (m: SyncMemoMap) => {
  + return (m: SyncMemoMap): Sy.Sync<R, E, A> => {
  const inMap = m.get(layer.hash.get)
  if (inMap) {
  return Sy.succeed(inMap)
  