Reflecting on the recent discussion on finding a better word for
"de-duplication" and in particular for "de-duplicated", here is what
name is used in Haskell:

nub                     :: (Eq a) => [a] -> [a]
nub                      = nubBy (==)

nubBy                   :: (a -> a -> Bool) -> [a] -> [a]
nubBy eq []              = []
nubBy eq (x:xs)          = x : nubBy eq (filter (\y -> not (eq x y)) xs)