Draft Regex Golf Bonus Levels

 1.0) Subtraction: http://regex.alf.nu/?set=096c2851405041e914554d6569c7b12b282e5b8c
 2.0) Anyway: http://regex.alf.nu/?set=e8bae464b482dfe68f03083276d8759ee4d0000c
 2.1) Anyway: http://regex.alf.nu/?set=12fda3525a9f0964e82f19c9b30333f15abf57ab
 3.0) Addition: http://regex.alf.nu/?set=a3598dad86891467275fe5b784902b093e01cc5b
 4.0) Coprime: http://regex.alf.nu/?set=04963affd55e2a487195995c9a9c8a3060ab0623
 5.0) Typist: http://regex.alf.nu/?set=814323f64b3028f3774526362d6516aba5c732e2
 6.0) Dominoes: http://regex.alf.nu/?set=d706fb7a1a939704a009d6d3da9e53217a733187
 6.1) Dominoes: http://regex.alf.nu/?set=9e055be1a701c710ca9ed731af041fa2d6a9d478
 7.0) Modulus: http://regex.alf.nu/?set=1d0701393c93cb937872f119ccfd5f4e13771c73
 8.0) Euclid: http://regex.alf.nu/?set=40da988035bc832a637fa95f1dd579c93396df69
 9.0) Latin squares: http://regex.alf.nu/?set=02c95a9dec7cc53c70c364ad5b56eb6e316f2821
 9.1) Latin squares: http://regex.alf.nu/?set=742eab557c42499e5222b6a4642fe6a46380669e
 9.2) Latin squares: http://regex.alf.nu/?set=d88f72524efafbbfe80c36dc449e3c176f72b544
 9.3) Latin squares: http://regex.alf.nu/?set=1981d2ca1b570c5b737e27517358eed59bca53a0
10.0) Matryoshka: http://regex.alf.nu/?set=f2c77b400ad20bc3b522205eb0cdd5b5f9184eb7
10.1) Matryoshka: http://regex.alf.nu/?set=08ae234d43f95d09112b460ee06f042c569eb79a
11.0) Dominoes 2: http://regex.alf.nu/?set=b1ffdd1dd77a92053acd5792bcec7271e8c599d5
11.1) Dominoes 2: http://regex.alf.nu/?set=4da7bda7ef6c5d5cb9ba79cdd25ec3ae5fd7c280
11.2) Dominoes 2: http://regex.alf.nu/?set=0c4a5a9e2e4e9695edfcf5b3f7f08e6dfe1ba81e
12.0) Xor: http://regex.alf.nu/?set=ec60e1f78681fba20f74384e2d378e81ebb42ec0
13.0) Tic-tac-toe: http://regex.alf.nu/?set=57a44278bbf89cd219f465cde985fe8f2f7f3294

I think that's enough puzzles for now. I'll spend what time I can spare for this on sharpening up the existing problems and solutions. Following this, I'll reassess the difficulties and re-order the problems.

The Dominoes 2 strings have been completely reworked to make the subtleties of the problem clearer and to increase the number of false positives for natural solutions to Dominoes.

Dominoes 2 strings were tweaked to include some very short chains (lengths 1 and 2). These cases trip up a number of natural solutions.

Dominoes 2 strings were redone in light of work done by Davidebyzero.

Would you mind me using your levels on my site? I already have Erling's levels (with his permission) and it would be cool if I could add yours as well. Of course I'd mention you as the author.

Not at all. Please use them as you wish.