I'm playing Regex Golf (http://regex.alf.nu/) and I'm doing the Abba hole. I have the following regex that matches the wrong side entirely (which is what I was trying to do):
(([\w])([\w])\3\2)
However, I'm trying to negate it now so it matches the other side. I can't seem to figure that part out. I tried:
(?!([\w])([\w])\3\2)
But that didn't work. Any tips from the regex masters?