1.hs

type IsoKey  = Int
-- | Serialized element
data ElementS = ElementS Int [IsoKey] 

data Element = Element Int [Isotope] deriving  (Show)
data Isotope = Isotope IsoKey Element deriving (Show) -- payload

to :: [ElementS] -> [Element] 
to es = let result = map (\(ElementS z keys) -> Element z (map (\k -> Isotope k (un help k)) keys)) es
	    help   = zip es result 
	in result
   where
     un :: [(ElementS, Element)] -> IsoKey -> Element
     un elms k = snd $ head $ filter (\((ElementS z isos),_) -> elem k isos) elms

test = to [ElementS 1 [11,12,13], ElementS 2 [22,23,24]]