Yesterday, I discovered regexle [1] and today found out that this was the inspiration for it.

I think I've seen this puzzle before, but I really enjoyed myself gradually solving it while doing other things in the last two hours. I'm sharing this for anyone else who wants a way to spend their afternoon!

[1]: https://regexle.com

Great puzzles! Didn't have so much fun puzzling for a long time.

That was pretty hard! It took me a bit over 2 hours. It took me a long time to get started, it felt impossible. But I found a lot of satisfying "ah ah!" moments that kept me going.

Really well done, but now I don't ever want to do one of these again.

It seems impossible?

On the left a horizontal must start with F: F.[AO].[AO].*

However, the diagonal for that cell may not include an F (aside from the start): [^X]*(DN|TE|NI)

https://blog.nelhage.com/post/regex-crosswords-z3/ was posted a few days ago here and is an interesting way to solve these

This is a really cool idea! It seems really hard though, I tried for a while and didn't get far. Would be keen to see one that's a little easier, maybe with less * qualifiers and more + or ?

I tried this for over 20 minutes and made almost zero progress because I thought the expressions also had to be words, like a crossword puzzle. Oops. It might be worth clarifying that somewhere.

For something a bit simpler I made redoku a while ago: https://padolsey.github.io/redoku/