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Hi shoeless,

A.I.C. in r3c5,
if r3c5=7 then r5c5=9 r4c6=1 r4c7=4 r3c7=1 r3c2=7 and too many 7 in row 3
so r3c5=9

Ciao Gianni

Thanks, that broke it free alright. Out of curiosity, how did y ...

Thanks, that helped me get a bit further to here. I'm thinking I should just move on to another puzzle. Laughing

+------------+----------------+----------------+
| 29 5 17 | 8 4 279 | ...

Anybody see a good next step in this one?

+---------------+----------------+-----------------+
| 29 5 17 | 8 4 279 | 3 6 127 |
| 234 8 347 | 1 6 237 | 47 9 ...

Swordfish got rid of some 7's, but I'm still stuck here

+-----------+--------+----------+
| 78 48 2 | 9 1 5 | 47 6 3 |
| 6 9 47 | 3 2 8 | 1 47 5 |
| 1 3 5 | 6 7 4 | 2 8 9 | ...

Thanks guys...I just wasn't seeing it. Once you get rid of the 3's in C6 it solves pretty easily.

I can't even get that far...how did you get rid of the 4's & 7's in the 4th row? I'm stuck here:

+----------------+---------------+-------------+
| 125679 8 23 | 3679 1679 137 | 4 1569 ...

nataraj,

Thanks! I caught the 8's on row 6 shortly after I made my post. It was the 79-57-59 xy wing that was eluding me. It fell into place once you pointed that out. In general, how do you sp ...

As Asellus said, this is known by many names and it's a common occurrence in many puzzles, though not always useful. It is two strongly linked chains on <7> (one marked A-a, one marked B-b) ...

I agree, nataraj's explanation of the logic was clear and made sense. It's always easy to see that stuff when someone points it out, but recognizing those patterns in the first place....that's where ...

nataraj,

Thanks for the tip on the naked quad. Other than eliminating a few candidates on r6, it didn't really get me over the hump. When you say "business in 2", do you mean box 2? If ...

Looked through the forum to see if this one had come up before, but there seems to be a big gap from about 10/06 to 5/07. Question

Anyway, I'm stuck on this one...

+-----------+---------------+-- ...

Welcome shoeless!

You can eliminate 2 from r4c5 using the xy-wing pivoted on (19) in r5c5 with pincers r2c5 and r4c6.

Steve

Thanks Steve, that's what I needed. Amazing how obvious it is whe ...

Ok...I've been staring at this for a while, but I'm obviously missing something. I don't fully get XY chains, but XY and XYZ wings make sense to me. In any case, I solved the puzzle to this point.
...