Replace (?=a)(?!a) with simply (?!).
Jeff japhy Pinyan, P.L., P.M., P.O.D, X.S.: Perl, regex, and perl hacker
How can we ever be the sold short or the cheated, we who for every service have long ago been overpaid? ~~ Meister Eckhart

In reply to Re^2: Delimited Backtracking with Regex by japhy
in thread Delimited Backtracking with Regex by neversaint

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