Sudoku Puzzles

Well, I wonder who took that photo.
Another lovely bit of photography fi. Well done.

Good morning to all! That is a very nice picture. Thanks Fi!

Maen you guys

Beautiful picture!

Did all four again. Great picture. Would love to vacation there.

Possible proof of not too tough sudoku of 12 04 06:
1) Start at 23 filled - the given puzzle. Unique Possibilities to 28 filled. (UP 28).
2a) Locked 6's at df9 forbids gh9=6
2b) Hidden triple 257 at bhi1 forbids b1=49,h1=346,i1=46
2c) Pair 25 at h19 forbids h567=25 UP 33
3a) Hidden More...

Just to tell you I do it with many guess Do we tell I resolve it?

I mean may we tell I resolve it?

Hi STEVE from Ohio,

I agree with you : today is not too tough - my way need 3 fc to solve with depth 6, your proof better but your step 3c is quite difficulty for me to follow. I understand that your proof step 3c that mean :
1- if a8=2 => a8<>3 (1)
2- if b8=2 => b1=7 More...

Darwin appears to be a beautiful place to hang out

Good Maen!! 14:43 - so I also agree with Steve that this one isn't very tough. Thanks for the pic, Fi!

Hi ttt!
My step 3c exposes one of the limitations of fc's. To convince yourself of such a limiation, try to write an fc for a naked triple. It does not 'fc' well. Step 3c presents better in matrix fashion, but I do not think well in matrices, so I prefer the fc presentation that I gave. More...

One obvious point I skipped in my explanation (perhaps not so obvious)
In this puzzle grid,
a8<>2 is equivalent to the existence of the coloring on 2's fc: g8==b8 -- a7 == a3.
BECAUSE: g8==b8=2 is true iff a8<>2 and
a7 == a3=2 is true if and only if (iff) a8<>2.
More...

Great - you all think it's not too tough, I had to have about 4 guesses to solve it. Bah.

Steve,

I am confused how bhi1 can have a hidden triple of b257 when b2 is given as a 5.

Would be nice to see water that's not frozen solid. Nice photo.

Nice photo fi, I have visitors coming for a couple of days and won't have time for this will catch up when they have gone. Have fun everyone. Oh HAPPY BIRTHDAY Kathy enjoy your day.

11:04
Beautiful evening... we call this part of sunset 'a blue moment'. Isn't it blue?

Okay....ATTENTION...ATTENTION

All guesses for the competition were lost in last week's big crash!!!!

You will need to redo them if you wish to be a part of the competition

Only 13 more days to due date so hopefully wont have to post these competition details for too much longer....

Competition.....Competition.......Competition

Guess the weight and date of arrival of my Grandbaby. Click on 'competition' and be in the running for 6 months free membership that Gath has so graciously offered.

To all who wish to take part in the competition...

If you go to 'check out my page' after my name you will see a photo of Nicole at 37 weeks. This may help in your guess. Some of you may wish to revise your guess...lol....Maybe the 'BIG CRASH' was a good thing

Hi Susan!
With hidden sets, just like with naked sets, it is not necessary that all the candidates of the hidden set be available in each cell. With hidden sets, it is necessary, in every case, that the candidates be limited to no more locations then the cells specified. Hopefully, this clears things up.

thanks Steve, of course that's right.

everyone. I am enjoying this nice warm weather down here in Florida. I am also enjoying a visit with my parents. (I think I left Michigan just in time.) Happy Birthday to all of you having Birthdays today. The pictures were interesting today. Have a good one everyone.

Sunset at east Point Darwint NT's romantic. Where ?

I completed the puzzle (didn't time myself though)and found it relatively easy for a tough. I often can't solve the tough ones. I figure I must have some smarts as I solved it without any guesses (did click the check answers button a bit) but for the life of me I cannot follow the explanations More...

Hi STEVE : thanks for your explainations ...

That one must have been easy! I got it out without looking to Steve for help. No guesses.

Hi platypus!
If one wishes to decipher the code used in proofs, the link 'proofs' below could lead to some help. Check through that link the link 'forbidding chains for ab. beginners'. Some day I hope to compile a group of pages that will make a complete understanding of the proofs and techniques somewhat less taxing then it is currently.

59 minutes

I found this a bit tough, contrary to what others said!

Completed on Oct. 31, 2007.

SE=7.2