sub nary_digits {
        my ($base, $digits) = @_;
        seq_from_spec( ([0..$base-1]) x $digits );
    }

    enumerate( nary_digits(2, 3) );  # 3-digit binary numbers

    #  0 => 0 0 0
    #  1 => 0 0 1
    #  2 => 0 1 0
    #  3 => 0 1 1
    #  4 => 1 0 0
    #  5 => 1 0 1
    #  6 => 1 1 0
    #  7 => 1 1 1