Tough Sudoku for 14/January/2008

all! Getting used to these evening puzzles!

16:40 Seemed an easy Tough

pretty flowers! it is raining here in the desert and really cold - we had to buy a heater! I will try to remember this feeling when it is 45 in July

Lovely shade of purple.

34:49

22 minutes. Basic techniques otherwise, but I needed to spot an fc resolving the cell i4 as the difficult step: the wrong choice quickly removes all the legal places for '3' from the top row.

Yep, a "hard" at best. Purty flower!

Very pretty flowers, Sue! Thanks.

Beautiful flowers.
Have a very nice time everyone.

18:06 Good mAen to you all.

This was an easy tough, more like a medium. During this weird time switch, when the new puzzle came so early that I've done it by time I get to the site again, I've gone into the archives to do some old puzzles again. The Toughs in May were definitely harder than the recent ones. The other amusement in the archives is that the comments no longer match the photos, so it's a bit of a mind bending experience to read the comments and imagine what the picture was originally.

I love clematis!

Absolutely gorgeous! So vivid! Thanks for the photo!

Just like the clematis here in Oregon. Must be a tough little vine to survive the OK winters, though sweetly non-invasive. Here, we like to snake them through the rhododendrums so there are blossoms on the rhoddies out-of-season.

We get an easy to make up for yesterday's tough. :)

Start 22
UP 25
1. Locked 1's (b23) forbids b4578=1
2. Locked 8's (bc5) forbids gh5=8
3. Locked 8's (bc7) forbids gh7=8
(X Wing wouid have saved the extra step.)
4. Locked 4's (g23) forbids g56=4
5. Hidden Pair 15 (i49) forbids i4=39; i9=368
6. Locked 4's (ac1) forbids de1=4
7. Hidden Pair 78 (b57) forbids b5=3; b7=369, Thus b8=9; b4=3; b1=2
8. Naked Pair 13 (c8, h8) forbids a8=1; d8=3; i8=1
9. Locked 3's (a789) forbids c7=3, Thus c8=3; h8=1; i9=5; i4=1...UP 81

Hi All,

Can someone show me a proof for puzzle today if it's EASY...
Thanks

Lovely flowers, lovely colour!! We used to have clematis when we lived in the New England, but too humid for them here.

Nice one today.. all basic rules. took 4 passes of rows and colums looking for stand alones

Joanne from Fairview, i don't understand a single thing you've said. How do you 'Locked' and 'Forbids' a number? And what will it do? Can you then un-Locked and un-Forbids? There is an X wing somewhere? Isn't that in Star Wars? There's even a NAKED pair? Where? I didn't see any...

I'm all stresses up now, think this game is more intense than i thought.

Joanne, I had trouble with your proof step 7. I saw the 78, but I also had sevens at b13. I thought that a hidden pair had to contain two numbers that appeared nowhere else in that column (row, box).

Good maeN, all.

Joanne, I follow your proof right up until you say Hidden Pair 78 (b57). I still have 7 as a possibility at b3, how did you eliminate this?

Cami & Jeff...I'll reprint the puzzle and see how I managed to get rid of the 7 at b3. Please check back. Hopefully, I can do this. Maybe I just got lucky.

Shaz, Locked numbers are fairly easy. You can probably find a clearer explanation on this website than I could come up with.

Cami & Jeff, I didn't write a very good proof. Naked Triple a1=247; b1=27; c1=47 forbids b2=7; b3=27; d1=47. Thus,
d1=8; i1=9. Though this takes care of 7 at b3, it still doesn't get rid of the 7 at b1. I'm sorry for throwing you off. I promise to be more careful. I don't know what I did as my notes didn't help much. Thanks for the questions. Where's Clark?????

Joanne, I believe that there are many reasons to post a proof, two that I can think of immediately are to have others verify the proof and so that we can discuss and learn from the that discussion. I very much enjoy when people post proofs so that I can learn from them and discuss them. Thank you for posting.

I'm not seeing the naked triple in abc1 because I still have 6 at a1 and b1 (as well as e1) in the possibility matrix. How did you eliminate the 6's in a1 and b1? In my matrix this would leave a hidden single for 6 at e1.

Thanks again

Jeff, I think you nailed the problem. My grid was messed up, which resulted in a 6 at e1 from the beginning. With that flaw, the rest was easy. Thanks for being kind.

Maybe a little kind but I was also sincere. We can't learn if we are afraid to make mistakes. I have only published one proof so far and that's because it was the only time I came up with a proof before someone else posted lol Keep on posting. I'm still working on this one by the way. I'm determined to get it now lol

So far the only progress that I have made is:
e3=1 == b3=1 -- b2=1 == b2=6 -- i2=6 == i3=6 forbids e3=6 and now as usual I am out of time to spend on it tonight.

help

Steve has posted a proof of this puzzle in his blog.

Got bogged down, while trying a different method. Finally solved it in 45 mts.

SE=8.3

18:44.