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!

54 posts
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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
- 2014 Supporter
**Posts:**2624**Joined:**15 May 2006

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
`Singles`

Almost Locked Set XZ-Rule: A=r4c125 - {2578}, B=r5c59 - {258}, X=2, Z=5 => r4c78,r5c2<>5

Singles

- hobiwan
- 2012 Supporter
**Posts:**321**Joined:**16 January 2008**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
`Singles`

Almost Locked Set XZ-Rule: A=r4c125 - {2578}, B=r5c59 - {258}, X=2, Z=5 => r4c78,r5c2<>5

Singles

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
- 2014 Supporter
**Posts:**2624**Joined:**15 May 2006

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

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
**Posts:**185**Joined:**20 October 2006**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

Four cells and four links. That I can understand.

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 remain

If 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
- 2014 Supporter
**Posts:**2624**Joined:**15 May 2006

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.

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
**Posts:**431**Joined:**27 January 2007**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
- 2014 Supporter
**Posts:**2624**Joined:**15 May 2006

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
- 2014 Supporter
**Posts:**2624**Joined:**15 May 2006

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
`Singles`

Almost Locked Set XZ-Rule: A=r4c125 - {2578}, B=r5c59 - {258}, X=2, Z=5 => r4c78,r5c2<>5

Singles

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
**Posts:**143**Joined:**14 March 2008

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
- 2014 Supporter
**Posts:**2624**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:

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`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
- 2014 Supporter
**Posts:**2624**Joined:**15 May 2006

54 posts
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