map length (tiers :: [[ Word2 ]])  =  [1,1,1,1]

length (list :: [ Word2 ])  =  4

allUnique (list :: [ Word2 ])  =  True

ratioRepetitions (list :: [ Word2 ])  =  0 % 1

tiers :: [Word2]  =
  [ [0]
  , [1]
  , [2]
  , [3]
  ]