You might want to read my bug report, and the discussion it triggered at http://bugs6.perl.org/rt2/Ticket/Display.html?id=10040. However, I think Perl is mistaken to think that (??{ }) generates a zero-width assertion.

Here's another way of doing it: 

    /^(\d)(?{local ($x, $c) = ($^N, 0)})
     ((\d)(?(?{$c ++; $^N == $x + $c})|\A))+$/x

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Abigail

In reply to Re: Code in regexp by Abigail-II
in thread Code in regexp by gjb

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