templates lexicalPermutations
  when <=1> do [1] !
  otherwise
    def n: $;
    def p: [ $n - 1 -> lexicalPermutations ];
    1..$n -> \(def k: $;
      $p... -> [ $k, $... -> \(when <$k..> do $+1! otherwise $!\)] !\) !
end lexicalPermutations

def alpha: ['ABCD'...];
[ $alpha::length -> lexicalPermutations -> '$alpha($)...;' ] -> !OUT::write