By the way, tuples *can* be members of Enum if you make them so. Try instance (Enum a, Enum b, Bounded b) => Enum (a,b) where toEnum n = (a, b) where a = toEnum (n `div` s) b = toEnum (n `mod` s) p = fromEnum (minBound `asTypeOf` b) q = fromEnum (maxBound `asTypeOf` b) s = q - p + 1 fromEnum (a, b) = fromEnum a * s + fromEnum b where p = fromEnum (minBound `asTypeOf` b) q = fromEnum (maxBound `asTypeOf` b) s = q - p + 1 data T1 = A | B | C deriving (Enum, Eq, Bounded, Show) data T2 = D | E | F deriving (Enum, Eq, Bounded, Show) t1 = [(A,D) .. (B,F)] I can't think of an approach that doesn't require all but one of the tuple elements to have Bounded types. There are of course all sorts of ways to enumerate tuples; this one is compatible with the Ord instance.