The New Sudoku Players' Forum

[StrmCkr]

Anyone who understands chains and ALSs is certainly capable of spotting and using any of these. Such multi-elimination end points are just rare catches, so they're not often seen. Still I'm quite sure I've used something like this several times.

fair enough : seen in manual solving, lacking in coded solvers

[SpAce]

fair enough : seen in manual solving, lacking in coded solvers

That might be true. However, have you checked this out? I haven't (and won't if it's Windows-only), but it mentions having an "AlsWWing" technique. I wonder if it could mean something like this.

[StrmCkr]

im not sure as i cant get it to open in win10

but i did manage to find a real world example for the idea

Code: Select all

+--------------------+------------------+---------------------+
| 1       23   236   | 4      3567  367 | 5678   568(3)  9    |
| (3467)  5    (346) | (367)  8     9   | (167)  2       1(3) |
| 367     9    8     | 1      3567  2   | 567    56(3)   4    |
+--------------------+------------------+---------------------+
| 2346    234  1     | 367    367   5   | 468    9       38   |
| 5       8    346   | 9      2     36  | 46-1   (136)   7    |
| 36      7    9     | 8      4     1   | 2      (36)    5    |
+--------------------+------------------+---------------------+
| 39      6    7     | 5      1     8   | 39     4       2    |
| 8       1    35    | 2      9     4   | 35     7       6    |
| 249     24   245   | 367    367   367 | 1589   158     18   |
+--------------------+------------------+---------------------+

for giggles ALS - W - RING

Code: Select all

+-------------------+----------------------+-------------------+
| 1     (478)  26-8 | (278)   9     (2468) | 27   5     3      |
| 9     (78)   5    | (278)   1     3      | 4    6     27     |
| 2346  34(7)  236  | 5-2(7)  (26)  45-26  | 9    1     8      |
+-------------------+----------------------+-------------------+
| 7     1      2389 | 6       238   289    | 358  4     59     |
| 23    39-8   4    | 12389   5     1289   | 6    3789  79     |
| 5     6      389  | 389     4     7      | 38   2     1      |
+-------------------+----------------------+-------------------+
| 8     349    1    | 2359    236   2569   | 27   379   245679 |
| 36    5      7    | 4       2368  2689   | 1    389   269    |
| 346   2      369  | 13589   7     15689  | 358  389   4569   |
+-------------------+----------------------+-------------------+


[tarek]

One to add here …

Code: Select all

+-------------------+-------------------+-------------------+
|*1367  2    *1369  | 4     13    5     | 39    8     3679  |
| 35    359   4     | 6     7     8     | 359   2     1     |
|*1357  8    *136   | 9     2     13    | 345   467   34567 |
+-------------------+-------------------+-------------------+
| 8     134   5     | 7     134   6     | 1349  149   2     |
|%134   6     2     |%13    8     9     | 7     5     34    |
| 9     134   7     | 2     5     34    | 6     14    8     |
+-------------------+-------------------+-------------------+
|^1456 ^145   8     |^15    9     7     | 2     3     456   |
| 2     1459  39-1  | 135   6     134   | 8     1479  4579  |
| 356   7     369-1 | 8     134   2     | 1459  1469  4569  |
+-------------------+-------------------+-------------------+
3 strong links (using 2 grouped strong links)
?3-Turbot Crane (using 2 grouped strong links)
1: * % ^ r89c3 <>1
b1 has an EmL type c/d
r57b1\c13b7 fins r13c3

With this one r7c1 is double covered which makes it a potential cannibalistic elimination

In sukaku explainer cannibalistic EE are not yet supported nor are endofins …
This would mean losing out on some useful (albeit more complicated) pattern eliminations. This may be something I can add as an option in the future

tarek

[SpAce]

Hi tarek,

?3-Turbot Crane (using 2 grouped strong links)

That's an interesting Grouped L1-Wing, but I don't see any resemblance to a Turbot Crane! I think the defining feature of the Crane is the EmR type of box-link, and we don't have that here. In fact, I don't see much resemblance to any Turbot Fish type, but the least of all the Crane. The elimination logic here is actually most similar to a Skyscraper (line & box covers). Thus, if anything, I think that's a very twisted Skyscraper.

That said, I'm not sure if it's a great idea to even try to name patterns like this after Turbot Fishes. Turbots are well-defined and easily recognized in their original two-strong-link forms, but extending that naming to more links has a strong potential to hurt more than help, I'm afraid. I think any named patterns should be so simple and well-defined that there's absolutely no confusion. For anything beyond that the more generic parent type is better. In this case Grouped L1-Wing/X-Chain would work, or Finned Franken Swordfish.

r57b1\c13b7 fins r13c3

Slightly simpler: r57b1\c134 f:r7c2; or avoiding the fin issue: (1)R57B1\c14[c3b7]

Btw, I think you should add the fish digit to the fish notation. I hate reading fishes where I have to look around for the actual digit, like in all the old fish discussions!! Not having a standard for that was a mistake in the UFG, I think.

With this one r7c1 is double covered which makes it a potential cannibalistic elimination

But only potential because it would need a third cover to get actually eliminated.

In sukaku explainer cannibalistic EE are not yet supported nor are endofins …
This would mean losing out on some useful (albeit more complicated) pattern eliminations. This may be something I can add as an option in the future

Cannibalism usually implies that simpler options exist, and endofins can usually be avoided too. So, I don't think it's missing out on much.

[SpAce]

Hi StrmCkr,

but i did manage to find a real world example for the idea

Code: Select all

+--------------------+------------------+---------------------+
| 1       23   236   | 4      3567  367 | 5678   568(3)  9    |
| (3467)  5    (346) | (367)  8     9   | (167)  2       1(3) |
| 367     9    8     | 1      3567  2   | 567    56(3)   4    |
+--------------------+------------------+---------------------+
| 2346    234  1     | 367    367   5   | 468    9       38   |
| 5       8    346   | 9      2     36  | 46-1   (136)   7    |
| 36      7    9     | 8      4     1   | 2      (36)    5    |
+--------------------+------------------+---------------------+
| 39      6    7     | 5      1     8   | 39     4       2    |
| 8       1    35    | 2      9     4   | 35     7       6    |
| 249     24   245   | 367    367   367 | 1589   158     18   |
+--------------------+------------------+---------------------+

True!

ALS-W-Wing: (1=63)r56c8 - r4c9 = r2c9 - (3467=1)r2c1347 => -1 r5c7

A bit simpler:

ALS-M-Wing: (1=63)r56c8 - r4c9 = (3-1)r2c9 = (1)r2c9 => -1 r5c7

for giggles ALS - W - RING

Code: Select all

+-------------------+----------------------+-------------------+
| 1     (478)  26-8 | (278)   9     (2468) | 27   5     3      |
| 9     (78)   5    | (278)   1     3      | 4    6     27     |
| 2346  34(7)  236  | 5-2(7)  (26)  45-26  | 9    1     8      |
+-------------------+----------------------+-------------------+
| 7     1      2389 | 6       238   289    | 358  4     59     |
| 23    39-8   4    | 12389   5     1289   | 6    3789  79     |
| 5     6      389  | 389     4     7      | 38   2     1      |
+-------------------+----------------------+-------------------+
| 8     349    1    | 2359    236   2569   | 27   379   245679 |
| 36    5      7    | 4       2368  2689   | 1    389   269    |
| 346   2      369  | 13589   7     15689  | 358  389   4569   |
+-------------------+----------------------+-------------------+


Also true! Yet another way to replace a Sue de Coq!

ALS-W-Ring: (4=8'7)r12c2 - r3c2 = r3c4 - (7'826=4)b2p1483 - loop => -8 r1c3,r5c2, -2 r3c4, -26 r3c6

--
PS. A simple ALS-W-Wing in today's puzzle as well.

--
Edit. A missed elimination and a typo corrected in the ALS-W-Ring, thanks to yzfwsf.

[tarek]

?3-Turbot Crane (using 2 grouped strong links)

That's an interesting Grouped L1-Wing, but I don't see any resemblance to a Turbot Crane! I think the defining feature of the Crane is the EmR type of box-link, and we don't have that here. In fact, I don't see much resemblance to any Turbot Fish type, but the least of all the Crane. The elimination logic here is actually most similar to a Skyscraper (line & box covers). Thus, if anything, I think that's a very twisted Skyscraper.

That said, I'm not sure if it's a great idea to even try to name patterns like this after Turbot Fishes. Turbots are well-defined and easily recognized in their original two-strong-link forms, but extending that naming to more links has a strong potential to hurt more than help, I'm afraid. I think any named patterns should be so simple and well-defined that there's absolutely no confusion. For anything beyond that the more generic parent type is better. In this case Grouped L1-Wing/X-Chain would work, or Finned Franken Swordfish.

Points taken,

Here is a new catch with 4 strong links:

Code: Select all

+----------------+----------------+----------------+
| 3   *469  5    | 679  4679 8    |%69   1    2    |
| 1   *469  2    | 3    469  49   | 5    7    8    |
|^679  8   ^79   | 5    1    2    | 3    4   ^69   |
+----------------+----------------+----------------+
| 2-9  7    3    | 4    8    19   | 26   5    16   |
|246-9 *69  49   | 129  239  5    | 7    8    13   |
| 5    1    8    | 27   237  6    | 24   9    34   |
+----------------+----------------+----------------+
|#479  2    6    | 8    5    479  | 1    3    479  |
| 8    3   #479  | 1269 2469 147  |%49   26   5    |
|#479  5    1    | 269  2469 3    | 8    26   479  |
+----------------+----------------+----------------+
4 Strong links (including blocks) 30121 (Using 3 grouped strong links)
9:*^%# r45c1<>9
9r1c27b7\r8b134 fins r79c1

This particular move reduces the puzzle to singles

[StrmCkr]

PS. A simple ALS-W-Wing in today's puzzle as well.

sweet

[tarek]

I'm hoping that this would be the last of the terminology sessions.

I came to the conclusion that the term Empty rectangle must only be used to describe a Single grouped strong link in a box where the inference of the strong link is derived from a mini-column and mini-row within that box.

We shouldn't therefore use "Empty rectangle" to describe a pattern of 2 strong links (one in a line and the other a grouped strong link in box). The term should be used to simplify the description of that Grouped strong link when used within a pattern (e.g. W-wing using an empty rectangle) (e.g. 2 strong links pattern using an empty rectangle)

the following is an attempt to categorize these Grouped strong links in location with a view to simplify description and reduce current confusion about terminology:

[code]Empty mini-Area (EmA):

I'm going to post this in advanced techniques as a separate thread to follow up on few updates to do with variants

tarek

[yzfwsf]

ALS-W-Ring: (4=8'7)r12c2 - r3c2 = r3c4 - (7'826=4)b2p1483 - loop => -8 r1c3, -2 r3c36, -6 r3c6

miss -8 r5c2

als_w_wing.PNG (26.02 KiB) Viewed 1331 times

[SpAce]

ALS-W-Ring: (4=8'7)r12c2 - r3c2 = r3c4 - (7'826=4)b2p1483 - loop => -8 r1c3, -2 r3c36, -6 r3c6

miss -8 r5c2

Yep, thanks! Looks like I also made a typo: should be -2 r3c46. Fixed.

Seems like your software works nicely. Does it run only on Windows?

[yzfwsf]

Seems like your software works nicely. Does it run only on Windows?

Yes.

[SpAce]

Seems like your software works nicely. Does it run only on Windows?

Yes.

Ok. Too bad.

[StrmCkr]

Real world example of a Dual|Ring xyz-hybrid elimination

Code: Select all

+---------------+--------------+------------+
| -5  (458)  -5 | /    /  (45) | -5  -5  -5 |
| -5  -5     -5 | /    /  /    | .   .   .  |
| /   (58)   /  | (5)  *  *    | /   /   /  |
+---------------+--------------+------------+
| .   -5     .  | .    .  .    | .   .   .  |
| .   -5     .  | .    .  .    | .   .   .  |
| .   -5     .  | .    .  .    | .   .   .  |
+---------------+--------------+------------+
| .   -5     .  | .    .  .    | .   .   .  |
| .   -5     .  | .    .  .    | .   .   .  |
| .   -5     .  | .    .  .    | .   .   .  |
+---------------+--------------+------------+

* may be missing candidate {5}
/ is missing {5}

found reddit post

Code: Select all

+-------------------+----------------+---------------+
| 2     (458)  4689 | 7     1   (45) | 3    9-5  68  |
| 46-5  7      469  | 3     24  8    | 1    59   26  |
| 3     (58)   1    | 2(5)  9   6    | 28   7    4   |
+-------------------+----------------+---------------+
| 9     12     23   | 8     5   7    | 4    6    13  |
| 7     6      34   | 129   24  1249 | 5    8    13  |
| 1458  148-5  48   | 6     3   14   | 7    2    9   |
+-------------------+----------------+---------------+
| 18    9      5    | 4     67  123  | 268  13   278 |
| 146   3      2467 | 125   8   125  | 9    14   27  |
| 148   1248   2478 | 129   67  1239 | 268  134  5   |
+-------------------+----------------+---------------+