map length (tiers :: [[ Nat2 ]])  =  [1,1]

length (list :: [ Nat2 ])  =  2

allUnique (list :: [ Nat2 ])  =  True

ratioRepetitions (list :: [ Nat2 ])  =  0 % 1

tiers :: [Nat2]  =
  [ [0]
  , [1]
  ]
