So close! It works almost all the time, but this test case fails: 
my @a = qw( a b c d e f g h i j k l m n o p q r s t u v w x y z );
my @b = qw( a b c X f g h X l m n X j k a b c d );

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Running on this, I get a b c as the result instead of a b c d. I'm looking to see if I can figure out why now, but I figured I'd post in case someone's faster than me (likely).

In reply to Re: Re: Finding largest common subset in lists? by anjiro
in thread Finding largest common subset in lists? by anjiro

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