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<?php $regex = '(((?!a)a)*)*a\\{'; $test_string = 'AAAAAAAAAAAAAA{AA'; echo "1:".mb_ereg_replace($regex,'WORKED',$test_string)."\n"; echo "2:".preg_replace('/'.$regex.'/u','WORKED',$test_string)."\n"; echo "3:".preg_replace('/'.$regex.'/','WORKED',$test_string)."\n";

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