The New Sudoku Players' Forum

[ArkieTech]

Code: Select all

 *-----------*
 |..4|..1|2..|
 |.3.|.8.|.4.|
 |6.8|...|7.1|
 |---+---+---|
 |.4.|.9.|..8|
 |...|1.5|...|
 |3..|.7.|.9.|
 |---+---+---|
 |9.7|...|5.4|
 |.8.|.2.|.1.|
 |..2|..6|8..|
 *-----------*


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[Leren]

Code: Select all

*--------------------------------------------------------------------------------*
| 57      579     4        | 3579    6       1        | 2       8       359      |
| 1257    3       159      | 2579    8       279      | 69      4       569      |
| 6       259     8        | 23459   345     2349     | 7       35      1        |
|--------------------------+--------------------------+--------------------------|
|a1257    4      a156      |a236     9      a23       | 13     a567     8        |
| 8       279     69       | 1      b34      5        | 34      67      27       |
| 3       25-1    156      | 2468    7       248      | 14      9       25       |
|--------------------------+--------------------------+--------------------------|
| 9       6       7        | 38      1       38       | 5       2       4        |
| 45      8       3        | 4579    2       479      | 69      1       679      |
| 145    c15      2        |c79     c45      6        | 8      c37     c379      |
*--------------------------------------------------------------------------------*

als xy-wing: (1=3) r4c13468 - (3=4) r5c5 - (4=1) r9c24589 => r6c2 <> 1; lclste

Leren

[tlanglet]

short chain........

1r9c2=1r6c2-(1=4)r6c7-r5c7=r5c5-(4=5)r9c5-(5=1)r9c2 => r9c2=1

[pjb]

A slight variation on the above, with same outcome:

(1=5) r9c2 - (5=4) r9c5 - (4=3) r5c5 - (3=4) r5c7 - (4=1) r6c7: => r6c2 <> 1

I would like to refer to Leren's nice ALS XY-wing as a 'Death Blossom', a much more colourful name.

Phil

[Marty R.]

Code: Select all

+--------------+----------------+------------+
| 57   579 4   | 3579  6   1    | 2  8   359 |
| 1257 3   159 | 2579  8   279  | 69 4   569 |
| 6    259 8   | 23459 345 2349 | 7  35  1   |
+--------------+----------------+------------+
| 1257 4   156 | 236   9   23   | 13 567 8   |
| 8    279 69  | 1     34  5    | 34 67  27  |
| 3    125 156 | 2468  7   248  | 14 9   25  |
+--------------+----------------+------------+
| 9    6   7   | 38    1   38   | 5  2   4   |
| 45   8   3   | 4579  2   479  | 69 1   679 |
| 145  15  2   | 79    45  6    | 8  37  379 |
+--------------+----------------+------------+


Play this puzzle online at the Daily Sudoku site

Longer and more-convoluted-than-necessary chain.

(5=1)r9c2-(145=7)r891c1-r4c1=r4c8-(7=3)r9c8-(3=5)r3c8-r12c9=r6c9=>r3c2,r6c2<>5

[DonM]

A slight variation on the above, with same outcome:

(1=5) r9c2 - (5=4) r9c5 - (4=3) r5c5 - (3=4) r5c7 - (4=1) r6c7: => r6c2 <> 1

I would like to refer to Leren's nice ALS XY-wing as a 'Death Blossom', a much more colourful name.
Phil

Leren's chain: (1=3) r4c13468(petal) - (3=4) r5c5(stigma) - (4=1) r9c24589(petal) => r6c2 <> 1

The term 'Death Blossom' originated some time ago for (in its simplest form) just such a chain wherein there are 2 ALSs of >=3 digits that flank a bivalue cell. The idea was that the flanking ALSs were like 'petals' radiating from the center of the flower and zeroing in on the target (digit).

Of course, if one looks on the bivalue cell as simply a very basic ALS, then a Death Blossom is (usually) a simple variant of an ALS xy-wing. I think the benefit of the term 'Death Blossom', other than being colorful, is that it makes a distinction from an ALS xy-wing of 3 ALSs of >=3 digits which to me is an ALS xy-wing as it was originally described.

Fwiw on this subject: I have trouble seeing an ALS xy-wing when 2 of the sets are bivalue cells. While, strictly speaking, a bivalue cell is a basic ALS, it is also just 2 digits and a strong link...

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