consistent' :: Approximation (UnionNF n (Interval Standard))
            -> UnionNF n Offsets
            -> ConsistencyResult
consistent' (Exact unf) ixs =
  case unfCompare unf ixs of
    EQ -> Consistent
    LT ->
      Inconsistent "The specification covers a smaller area than the indices."
    GT ->
      Inconsistent "The specification covers a larger area than the indices."
consistent' :: Approximation (UnionNF n (Interval Standard))
            -> UnionNF n Offsets
            -> ConsistencyResult
consistent' (Exact unf) ixs =
  case unfCompare unf ixs of
    EQ -> Consistent
    LT ->
      Inconsistent "The specification covers a smaller area than the indices."
    GT ->
      Inconsistent "The specification covers a larger area than the indices."
consistent' (Exact unf) ixs =
  case unfCompare unf ixs of
    EQ -> Consistent
    LT ->
      Inconsistent "The specification covers a smaller area than the indices."
    GT ->
      Inconsistent "The specification covers a larger area than the indices."