## Rambling

Everything about Sudoku that doesn't fit in one of the other sections
ttt wrote:I present your elimination r8c9=4 by using dual Kraken - 3's on row 3 and cell r1c7 :

I can barely follow basic Eureka notation. Your original chains were at my limit for understanding. Sorry!
daj95376
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My solver finds: Singles, a short Chain, and Singles. Does it have a more zippy solution?

Code: Select all
` +-----------------------+ | 5 4 . | . 6 . | . . 3 | | 2 . . | . . 9 | . . . | | . . 9 | 4 5 . | . . 2 | |-------+-------+-------| | . . 6 | 9 . 3 | . . 1 | | 1 . 4 | . . 7 | 9 . . | | . 2 . | 1 4 5 | . . . | |-------+-------+-------| | . . . | . 1 . | . . . | | . . . | . . . | . 7 . | | 4 . 5 | 7 . . | . . 9 | +-----------------------+`
daj95376
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daj95376 wrote:My solver finds: Singles, a short Chain, and Singles. Does it have a more zippy solution?

My solver finds a few ALS to replace the chain, but nothing special. One possibility:

Code: Select all
`SinglesAlmost Locked Set XZ-Rule: A=r4c125 - {2578}, B=r5c59 - {258}, X=2, Z=5 => r4c78,r5c2<>5Singles`
hobiwan
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Location: Klagenfurt

hobiwan wrote:
daj95376 wrote:My solver finds: Singles, a short Chain, and Singles. Does it have a more zippy solution?

My solver finds a few ALS to replace the chain, but nothing special. One possibility:

Code: Select all
`SinglesAlmost Locked Set XZ-Rule: A=r4c125 - {2578}, B=r5c59 - {258}, X=2, Z=5 => r4c78,r5c2<>5Singles`

Thanks for checking hobiwan! FWIW: your ALS produces the same eliminations as my short chain. Since there are plenty of backdoor singles to crack this PM, maybe there's an obscure UR/DP present as well. Heck, there may even be a Kraken fish -- something I forgot to check.
daj95376
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Hi Daj,
My solutions :

1) [r4c2]=5=[r5c2]-5-[r5c9]-8-[r5c5]=8=[r4c5]-8-[r4c1]-7-[r4c2] => r4c2<>7, singles
2) [r6c3]-8-[r4c1]-7=[r4c2]=7=[r3c2]-7- ALS:([r12c3]=1|8=[r12c3])-8-[r6c3] => r6c3<>8, singles
3) [r6c3]-8-[r4c1]-7-[r7c1]=7=[r7c3](-3-[r7c3])=2=[r8c3](-3-[r8c3])-3-[r6c3] => r6c3<>8, singles

I’m not sure for presenting my solutions 2 & 3, I’m new for NL notation...

BTW, thanks to you and Ronk for helping me to learn NL notation.

ttt
ttt

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Location: vietnam

I must admit that I've deliberately avoided learning ALS. Some things make my head go TILT.

http://forum.enjoysudoku.com/viewtopic.php?p=60713#p60713

999_Springs wrote:Then I found an ALS xz
ALS A=r7c46r8c5r9c6
ALS B=r456c5r5c6
x=1 z=7 r8c6<>7
(It's not that necessary but I hardly ever find these things, so I might as well use it...)

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` +--------------------------------------------------------------------------------+ |  69      5       2       |  4       8       1       |  79      3679    367     | |  4689    346     348     |  69      7       569     |  1       24569   24568   | |  4689    17      17      |  3       2       569     |  4589    4569    4568    | |--------------------------+--------------------------+--------------------------| |  456     1467    1457    |  8      B1469    2       |  4579    134579  13457   | |  3       124     1458    |  179    B149    B479     |  6       12459   12458   | |  2468    9       1478    |  5      B146     3       |  2478    1247    12478   | |--------------------------+--------------------------+--------------------------| |  1       248     6       | A79      3      A4789    |  2457    2457    2457    | |  245     234     345     |  167    A14      46-7    |  2347    8       9       | |  7       348     9       |  2       5      A48      |  34      16      16      | +--------------------------------------------------------------------------------+ # 136 eliminations remainIf we start with:            [r8c6]-7-[r5c6]There is a strong link on 7: [r5c6]=7=[r5c4]There is a strong link on 1: [r5c4]=1=[r8c4]There is a strong link on 6: [r8c4]=6=[r8c6]`

Four cells and four links. That I can understand.
daj95376
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I don't look for these ALSs on purpose. I still have a lot of trouble finding them. That one basically just came out at me for no reason at all. I will now say that this is only the second ALS elimination I have ever found.

There might be a simpler ALS elimination for all I know. (If there is then I can't find it.)

I was never able to find ALSs effectively. I will add a link to show that when I have the time.
Once upon a time I was a teenager who was active on here 2007-2011
ocean and eleven should have paired up to make a sudoku-solving duo called Ocean's Eleven
999_Springs

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Location: In the toilet, flushing down springs, one by one.

999_Springs wrote:I was never able to find ALSs effectively. I will add a link to show that when I have the time.

I was not criticizing you or your post. I find ALS eliminations to be foreign when compared to chains that often perform the same eliminations. Your ALS was just a convenient example.
daj95376
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Is there a name for a pattern where identical XY cells are pincers in a (possibly grouped) chain of >4 cells linked by X such that either end must be true for Y

Code: Select all
`9-[r6c1]-3-[r3c1]=3=[r3c5]-3-[r12c4]=3=[r8c4]-3-[r8c2]-9`
daj95376
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because W seems to be the trend now ...

tarek

tarek

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Ahhhhhh, thanks tarek for reminding me of ronk's suggestion awhile back. My memory is swiss cheese anymore

I also found a 2007 entry in the Daily Sudoku Forum where keith calls it a General Remote Pair.

I like both designations.
daj95376
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Hi Danny,
I don’t know why, but I like you… Perhaps, because of WE like SUDOKU…

ttt
ttt

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Location: vietnam

daj95376 wrote:
hobiwan wrote:
daj95376 wrote:My solver finds: Singles, a short Chain, and Singles. Does it have a more zippy solution?

My solver finds a few ALS to replace the chain, but nothing special. One possibility:

Code: Select all
`SinglesAlmost Locked Set XZ-Rule: A=r4c125 - {2578}, B=r5c59 - {258}, X=2, Z=5 => r4c78,r5c2<>5Singles`

Thanks for checking hobiwan! FWIW: your ALS produces the same eliminations as my short chain. Since there are plenty of backdoor singles to crack this PM, maybe there's an obscure UR/DP present as well. Heck, there may even be a Kraken fish -- something I forgot to check.

Weighing in waaay late... another simple forcing chain that cracks the puzzle (after the initial Singles pass):
Code: Select all
`r5c2=3 r6c3=8 + r5c8=3 r5c5=2 r4c5=8 ==> r4c1<>8`

Cheers...

- drac
Draco

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ttt wrote:Hi Danny,
I don’t know why, but I like you… Perhaps, because of WE like SUDOKU…

Thanks ttt, it's always nice to be liked

I'm just sorry that I only understand some of the replies you took time to post. Maybe some day, I'll understand Eureka! notation better.

I may often be difficult, but I like you and many other members of this forum as well.
daj95376
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Joined: 15 May 2006

Draco wrote:Weighing in waaay late... another simple forcing chain that cracks the puzzle (after the initial Singles pass):
Code: Select all
`r5c2=3 r6c3=8 + r5c8=3 r5c5=2 r4c5=8 ==> r4c1<>8`

Cheers...

Hello Draco,

Yes, your forcing chain does the job very nicely. Did you consider converting it into:

Code: Select all
`8-[r6c3]-3-[r5c2]=3=[r5c8]=2=[r5c5]-2-[r4c5]-8 => [r4c12]<>8`

To me, the above AIC chain is a forcing chain based on the bivalue candidates in [r6c3] -- or the bivalue candidates in [r4c5].
daj95376
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Joined: 15 May 2006

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