The New Sudoku Players' Forum

[ArkieTech]

Code: Select all

 *-----------*
 |6.9|5..|4..|
 |5..|.4.|.63|
 |.4.|6.8|9..|
 |---+---+---|
 |4..|.53|...|
 |...|.7.|...|
 |...|42.|..6|
 |---+---+---|
 |..6|7.5|.3.|
 |73.|.9.|..8|
 |..4|..2|5.7|
 *-----------*


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[SteveG48]

Code: Select all

 *-----------------------------------------------------------*
 | 6     28    9     | 5     3     7     | 4    d18   d12    |
 | 5    c178   178   | 2     4     9     |d78    6     3     |
 | 23    4     237   | 6     1     8     | 9     7-5  d25    |
 *-------------------+-------------------+-------------------|
 | 4     6     1278  | 89    5     3     | 278   178   19    |
 | 1238  1258  1238  | 89    7     6     | 238   4     159   |
 | 389  b5789  378   | 4     2     1     | 378  a578   6     |
 *-------------------+-------------------+-------------------|
 | 29    29    6     | 7     8     5     | 1     3     4     |
 | 7     3     5     | 1     9     4     | 6     2     8     |
 | 18    18    4     | 3     6     2     | 5     9     7     |
 *-----------------------------------------------------------*


5r6c8 = (5-7)r6c2 = r2c2 - (7=1258)b3p2349 => -5 r3c8 ; stte

[Leren]

Code: Select all

*--------------------------------------------------------------*
| 6     28    9      | 5     3     7      | 4     18    12     |
| 5    c178   178    | 2     4     9      | 78    6     3      |
| 23    4    b237    | 6     1     8      | 9    a7-5   25     |
|--------------------+--------------------+--------------------|
| 4     6     1278   | 89    5     3      | 278   178   19     |
| 1238  1258  1238   | 89    7     6      | 238   4     159    |
| 389  d5789  378    | 4     2     1      | 378  e58-7  6      |
|--------------------+--------------------+--------------------|
| 29    29    6      | 7     8     5      | 1     3     4      |
| 7     3     5      | 1     9     4      | 6     2     8      |
| 18    18    4      | 3     6     2      | 5     9     7      |
*--------------------------------------------------------------*

L2 Wing: (7) r3c8 = r3c3 - r2c2 = (7-5) r6c2 = (5) r6c8 => - 5 r3c8, -7 r6c8; stte

Leren

[Cenoman]

Code: Select all

 +----------------------+----------------+-------------------+
 | 6     b28     9      | 5    3    7    | 4     18    12    |
 | 5     b178    178    | 2    4    9    | 78    6     3     |
 |a23     4     a237    | 6    1    8    | 9     57   a25    |
 +----------------------+----------------+-------------------+
 | 4      6      1278   | 89   5    3    | 278   178   19    |
 | 1238  b1258   1238   | 89   7    6    | 238   4     19-5  |
 | 389    5789   378    | 4    2    1    | 378   578   6     |
 +----------------------+----------------+-------------------+
 | 29    b29     6      | 7    8    5    | 1     3     4     |
 | 7      3      5      | 1    9    4    | 6     2     8     |
 | 18    b18     4      | 3    6    2    | 5     9     7     |
 +----------------------+----------------+-------------------+


(523=7)r3c139 - (7=12895)r12579c2 =>- 5 r5c9; stte

I guess this might be called ALS=XZ rule.
Cenoman

[Ngisa]

Code: Select all

+--------------+--------+-------------+
| 6  28   9    | 5  3 7 | 4   18  12  |
| 5  c178  178  | 2  4 9 | d78  6   3   |
| 23 4    237  | 6  1 8 | 9   e57  f25  |
+--------------+--------+-------------+
| 4  6    1278 | 89 5 3 | 278 178 19  |
| 18 a1258 1238 | 89 7 6 | 238 4   19-5 |
| 39 b5789 378  | 4  2 1 | 378 578 6   |
+--------------+--------+-------------+
| 29 29   6    | 7  8 5 | 1   3   4   |
| 7  3    5    | 1  9 4 | 6   2   8   |
| 18 18   4    | 3  6 2 | 5   9   7   |
+--------------+--------+-------------+


(5)r5c2 = (5-7)r6c2 = r2c2 - r2c7 = (7-5)r3c8 = (5)r3c9 => -5 r5c9; stte

Clement

[Sudtyro2]

Code: Select all

 *-------------------------------------------------------*
 | 6     28    9     | 5     3     7  |  4    18    12   |
 | 5    f178   178   | 2     4     9  | g8-7  6     3    |
 | 23    4     23-7  | 6     1     8  |  9  ha57   b25   |
 |-------------------+----------------+------------------|
 | 4     6     1278  | 89    5     3  |  278  18-7  19   |
 | 1238 d1258  1238  | 89    7     6  |  238  4    c159  |
 | 389  e5789  378   | 4     2     1  |  378  58-7  6    |
 |-------------------+----------------+------------------|
 | 29    29    6     | 7     8     5  |  1    3    4     |
 | 7     3     5     | 1     9     4  |  6    2    8     |
 | 18    18    4     | 3     6     2  |  5    9    7     |
 *-------------------------------------------------------*

Discontinuous loop.
(7=5)r3c8 - r3c9 = r5c9 - r5c2 = (5-7)r6c2 = r2c2 - r2c7 = 7r3c8 => -7r3c3,r2c7,r46c8; stte

SteveC

[Leren]

Cenoman wrote : (523=7)r3c139 - (7=12895)r12579c2 =>- 5 r5c9; stte I guess this might be called ALS=XZ rule.

It certainly can : X = 7 is the restricted common digit and Z = 5 is the pincer (elimination) digit.

I prefer to write it as (5=7) r3c139 - (7=5) r12579c2, whether you write it your way or mine has been the subject of some discussion over the years.

There are relative advantages/disadvantages of writing it either way. Even the pedants are silent on this issue.

Leren

[Cenoman]

Leren wrote:
I prefer to write it as (5=7) r3c139 - (7=5) r12579c2, whether you write it your way or mine has been the subject of some discussion over the years.

The advantage of writing it Leren's way is obvious in the example of this puzzle. My way is rather cumbersome. But ALS's of 5 cells or more are not that frequent.
No trouble for me to read your writing.
I just try to stick to the Eureka notation as expressed here http://sudopedia.enjoysudoku.com/Eureka.html
I try also to be in accordance with preferences of users registered for long when entering a new forum. So if your preference is commonly shared in this forum, let me know.
I put just one argument on the table: when I use an AHS in a chain I write it the same way, e.g. (123-4) r1c123 (fictitious example), the symbol weak link replacing the symbol strong link. In the case of AHS's the weak link is useful for alternance in an AIC, only between two digits, in my example (1-4) r1c123. But writing it this way leaves to the reader the task to identify the locked digits in the AHS cells (less easy than with ALS). ALS's and AHS's are duale objects, therefore I prefer to write them similarly. I agree this to be a matter of taste and colours...
As stated a few days ago (page November 26,2016): the important point is substance, rather than style. Another important point is the pleasure to have the puzzle solved (even without issuing one's path)

Cenoman