$val = 'BB';
incr($val);  ==> 'BC'

$val = 'BZ';
incr($val);  ==> 'CB';

$val = 'ZZ';
incr($val)  ==> 'BBB';

##</code><code>##

#!/usr/bin/env perl

use strict;
use warnings;
use Math::Fleximal;
# use Data::Dump;
use feature qw (say);

my @consonants = qw (B C D F G H J K L M N P Q R S T V X Y Z);

my $number = Math::Fleximal->new( "BB", \@consonants );

say $number->to_str();
say $number->base_10();

$number = $number->add("C");

say $number->to_str();
say $number->base_10();

say qq(--);

$number = $number->set_value("BZ");

say $number->to_str();
say $number->base_10();

$number = $number->add("C");
say $number->to_str();
say $number->base_10();

say qq(--);

$number = $number->set_value("ZZ");

say $number->to_str();
say $number->base_10();

$number = $number->add("C");
say $number->to_str();
say $number->base_10();

__END__

karls-mac-mini:monks karl$ ./fleximal.pl
B
0
C
1
--
Z
19
CB
20
--
ZZ
399
CBB
400