one :: Int -> LeftTransformation a
one nrs
  | nrs >= 0 = LeftTransformation nrs V.empty
  | nrs < 0 = error "LeftTransformation.one: negative nrs"
one :: Int -> LeftTransformation a
one nrs
  | nrs >= 0 = LeftTransformation nrs V.empty
  | nrs < 0 = error "LeftTransformation.one: negative nrs"
one nrs
  | nrs >= 0 = LeftTransformation nrs V.empty
  | nrs < 0 = error "LeftTransformation.one: negative nrs"