Eigenschaften
code und deco sind invers zu einander:
deco p k (code p k n) = n if n `below` p^k
code p k (deco p k xs) = xs if digits p k xs
code p (j+k) (m * p^k + n) = code p j m ++ code p k n
if m `below` p^j && n `below` p^k
deco p (j+k) (xs ++ ys) = (deco p j xs) * p^k + deco p k ys
if digits p j xs && digits p k ys