Regexp puzzles!

I've been trapped into this http://regexcrossword.com/ for  the whole afternoon...  Pretty cool pastime.

I guess I'd enjoy a bit more complicated one with more usage of recursion, backreferences, and maybe lookaheads...  But it's fine.  A nice exercise to get your brain spinning for a while.

I'm now back to my haskell lectures.   Oh yeah, I'm trying to learn Haskell.

Again