Sudoku Puzzles

Good Maen. Looks like a basket of fruit.

This is unique. Is it a hanging basket with flowers?

It looks like it will be a cool, sunny, fall day here. We are getting a lot of 'fall colors'. Have a great day everyone.

7:23 Maen

Unusual. Not sure why you would want to use that to mark a grave though.

We've got sun here too, Debby; a nice relief from yesterday's storm. Enjoy your day, everyone!

We're getting all the rain here in northern CA. Unusual for us this time of year.

a long proof which begs to be simplified, classical depth 5 at least:

1) Start with 22, UP 24
2) Naked Triple: adf6=569 => ~bgi6=569
3) Naked Triple: abc2=369 => ~dghi2=369
4) Locked: df6=9, ghi5=2, ghi2=8 => ~((e5, df4)=9, hi4=2, gh1=8)
5) Naked Pair: e75=46 => More...

other pic from Utah, it look like big fungus.

Possible proof of tough sudoku of 10 06 06:

1) Start at 22 filled - the given puzzle. Unique Possibilities to 24 filled. (UP 24).
2a) Naked triple 56,569,69 at adf6 forbids bgi6=56, bg6=9,df4f5=9
2b) h9=3 == g7=3 -- g6=3 == g6=8 -- g2=8 == h2=8 -- h2=7 == h1=7 forbids More...

Finally. Took me 59:43

To get to UP 38, Pat's proof and mine are very similar. To finish from there, our paths diverge a tad.

To Pat: YOur step 17b would be classical depth 7. I am still not completely convinced that calling such a step depth 4, as it is written with 4 strong links, is entirely logical.

In any event, step 17a in your proof is especially elegant. One could also write the step as a Sue de Cox, I More...

As a point of interest, the cell that Pat considered - f9, is a rare lexus point involving the little used, and barely understood technique of 6 choose 4. Using this technique, one can directly solve the cell f9=4.

The technique looks at the possible values of the 6 memeber vectors More...

forget the timer Nick and just enjoy the game.
mAen all

The technique is a direct result of the rules of the game:
For example, let a1=A,a2=B,a3=C,b1=D,c1=E
Then a456789={DEFGHI} and defghi1=(ABFGHI}
Common members of these two vectors is: FGHI - exactly 4. QED.
There is no loss of generality in this rather non-mathematical analysis.
More...

The breakdown of the logic can be seen in this matrix:
f9=4 a9=4 b9=4
0000 a9=5 b9=5
f9=2 a9=2 0000 d9=2
f9=2 0000 0000 f8=2 f4=2
f9=4 0000 0000 0000 f4=4
a9=5 b9=5
a9=4 b9=4 f9=4

oops - delete the last two lines - it should just be a 5 by 5 matrix. Conclude then f9=2 == f9=4. Hopefully this makes sense to someone ....

6:20

I'm sorry this photo isn't more clear. This photo is a pair of horseshoes holding a varnished log slice with a poem attached that the person who died had written about how much she loved this area (Dry Fork Canyon in Utah). This old, small cemetery has no formal landscaping, but only personal More...

I always thought I was intelligent, but I cannot find those chains when I look. but can follow them when you put them up. Are you all (well errr Steve, Pat, Meg and a few others) some kind of idiots savants, like the ones who could do the Rubik cubes?
All of the logic I follow, and it works, but More...

That was really a serious question. My IQ was (before I started drinking) about 155, but obviously this is not my forte. Would really interest me to know if you do it by looking or with some assistance.

I discount the ones who say they are all easy and finish them in 3:53 etc,

Hi John!
The idiot part probably resembles me more closely then the savant.
I wish that I could put forth a precise manner of investigation that would consistently lead to the best, shortest chains towards a solution of a difficult puzzle, but I think part of the charm of these puzzles is More...

Hi Steve,
You are the one I watch most. I always appreciated your proofs, because you stick to a format that is comprehensible. You did not answer my question about whether you use some kind of aid :)

Makes me feel by brain is lacking somewhere, because I always get the highest ratings (by far) on all the usual tests.

Important is that you somehow see the chains.

All of you good guys suffer from typos, but that is maybe part of the syndrome. Keep on doing the proofs, cos maybe it will one day improve my brain.

1) Start 22, Unique Possibilities to (UP) 24.
2) Naked triplet a6=56, d6=569, f6=69 forbids b6=569, g6=569, i6=56.
3) Locked 9s at df6 forbid df4=9, e5=9.
4) Hidden pair 89 at e19 forbids e1=36, e9=46. UP 25.
5) Naked triplet a2=36, b2=69, c2=369 forbids d2=69, g2=36, h2=36, More...

Hi John!
I always put the puzzle into the program Simple Sudoku. It does not find fc's, but it is very helpful in the following:
I can save the puzzle at various states - helps in proof writing more than in proof finding.
I can highlight certain candidates - very helpful in finding More...

Here is a puzzle that I created that illustrates perhaps an interesting new technique, waiting to be formalized, that Pat made me think of with her proof today. There are many normal fc's available, so try to prove it not using anything normal. It requires exactly 4 sets, depth 4 to solve, using More...

one guess

Oct. 15, 2007.