Just a variant that takes the rules of the original question a little more literally and strictly ...

use strict;
use warnings;
my $abc = "AABCBAABCCCCAB";
my $ab  = "AABABAABABABAB";
$abc =~ s/C/[AB]/g;
$abc = qr/^$abc$/;
print "They match!\n" if $ab =~ $abc;

[download]
Ron

In reply to Re^2: Tri state string compare? by mr_ron
in thread Tri state string compare? (Solved! see update2) by BrowserUk

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