-- | @nubOrdBy f = nubBy (equaling f)@
propNubOrdBy :: Int -> [(Int, Int)] -> Bool
propNubOrdBy i = uncurry (==) . map21 (nubOrdBy fst, nubBy $ equaling fst)
propNubOrdBy :: Int -> [(Int, Int)] -> Bool
propNubOrdBy i = uncurry (==) . map21 (nubOrdBy fst, nubBy $ equaling fst)
propNubOrdBy i = uncurry (==) . map21 (nubOrdBy fst, nubBy $ equaling fst)