The New Sudoku Players' Forum

[ArkieTech]

Code: Select all

 *-----------*
 |.5.|.8.|...|
 |..9|3..|4.1|
 |..1|5..|..8|
 |---+---+---|
 |4..|1..|...|
 |..6|.4.|5..|
 |...|..3|..2|
 |---+---+---|
 |6..|..7|2..|
 |2.7|..8|3..|
 |...|.3.|.9.|
 *-----------*


Play/Print this puzzle online

[Leren]

Code: Select all

*--------------------------------------------------------------*
| 37    5    e24     |f49-26 8     1      | 679   2367  3679   |
| 8     26    9      | 3     7    a26     | 4     5     1      |
| 37    246   1      | 5    b269   2469   | 679   2367  8      |
|--------------------+--------------------+--------------------|
| 4     2378 d2358   | 1    c2569  2569   | 6789  3678  3679   |
| 19    12378 6      | 78    4     29     | 5     1378  379    |
| 159   178   58     | 78    569   3      | 16789 4     2      |
|--------------------+--------------------+--------------------|
| 6     13489 3458   | 49    159   7      | 2     18    45     |
| 2     149   7      | 469   1569  8      | 3     16    456    |
| 15    148   458    | 246   3     2456   | 1678  9     4567   |
*--------------------------------------------------------------*

(6=2) r2c6 - r3c5 = r4c5 - r4c3 = (2-4) r1c3 = (4) r1c4 => -26 r1c4; stte

Leren

[Cenoman]

Code: Select all

 +----------------------+----------------------+-----------------------+
 | 37    5      h2-4    | 2469   8      1      | 679     2367   3679   |
 | 8    k26      9      | 3      7      26     | 4       5      1      |
 | 37  bk246     1      | 5      269   a2469   | 679     2367   8      |
 +----------------------+----------------------+-----------------------+
 | 4     2378   g2358   | 1      2569  c2569   | 6789    3678   3679   |
 | 19   j12378   6      | 78     4     i29     | 5       1378   379    |
 | 159   178     58     | 78     569    3      | 16789   4      2      |
 +----------------------+----------------------+-----------------------+
 | 6     13489  f3458   | 49     159    7      | 2       18     45     |
 | 2     149     7      | 469    1569   8      | 3       16     456    |
 |e15    148    e458    | 246    3     d2456   | 1678    9      4567   |
 +----------------------+----------------------+-----------------------+

 Kraken column (9)r345c6
 (9-4)r3c6 = (4)r3c2                                      -4 r1c3

 (9-5)r4c6 = r9c6 - r9c13 = (5-3)r7c3 = (3-2)r4c3 = r1c3 - 4 r1c3

 (9-2)r5c6 = r5c2 - (2=4)r23c2                           - 4 r1c3; stte

Not easy to find not yet issued 1-steppers to day, as well as days before...
Cenoman

[eleven]

(6=2) r2c6 - r3c5 = r4c5 - r4c3 = (2-4) r1c3 = (4) r1c4 => -26 r1c4; stte

The chain does not show, that 2 can be eliminated from r1c4. Should be something like
(26)r2c6,r3c5 = (9-2)r3c5 = r4c5 - r4c3 = (2-4) r1c3 = (4) r1c4 => -26 r1c4; stte

[bat999]

... Should be something like...

I wasn't able to find a solution myself, I gave up.
But now I see it similar to eleven.

Code: Select all

.-------------------.----------------------.-------------------.
| 37   5      b24   | a49-26   8      1    | 679    2367  3679 |
| 8    26      9    |  3       7     e26   | 4      5     1    |
| 37   246     1    |  5      e269    2469 | 679    2367  8    |
:-------------------+----------------------+-------------------:
| 4    2378   c2358 |  1      d2569   2569 | 6789   3678  3679 |
| 19   12378   6    |  78      4      29   | 5      1378  379  |
| 159  178    c58   |  78     d569    3    | 16789  4     2    |
:-------------------+----------------------+-------------------:
| 6    13489  c3458 |  49     d159    7    | 2      18    45   |
| 2    149     7    |  469    d1569   8    | 3      16    456  |
| 15   148    c458  |  246     3      2456 | 1678   9     4567 |
'-------------------'----------------------'-------------------'

(4)r1c4 = r1c3 - (4=2)r4679c3 - (2=9)r4678c5 - (9=26)r2c6,r3c5 => -26 r1c4; stte

[Leren]

(6=2) r2c6 - r3c5 = r4c5 - r4c3 = (2-4) r1c3 = (4) r1c4 => -26 r1c4; stte

The chain does not show, that 2 can be eliminated from r1c4. Should be something like
(26)r2c6,r3c5 = (9-2)r3c5 = r4c5 - r4c3 = (2-4) r1c3 = (4) r1c4 => -26 r1c4; stte

Well it does to me. Perhaps I could have been more explicit and written (6=2) r2c6 - (2) r3c5 = r4c5 - r4c3 = (2-4) r1c3 = (4) r1c4 => -26 r1c4

The full chain => - 6 r1c4 and ignoring the first term you get (2) r3c5 = r4c5 - r4c3 = (2-4) r1c3 = (4) r1c4 => - 2 r1c4, so both eliminations are justified.

You could call this move an example of an embedded AIC, or an L2 wing with extension cell r2c6. I learnt this move some years ago on another forum but I only use it when I am desperate. The stte moves posted by others were more complex.

If there is any controversy about this move (apart from notational issues, which I always consider pedantic and boring) is : is this really two separate moves rolled into one ?

Possibly, but then there is no "rule" that says that you can't post a two move solution, so I don't mind posting this move occasionally.

Leren

[SteveG48]

Well it does to me.

And to me as well. I've never come up with one of these, but I love it on those rare occasions that Leren puts one up.

[eleven]

Well it does to me. Perhaps I could have been more explicit and written (6=2) r2c6 - (2) r3c5 = r4c5 - r4c3 = (2-4) r1c3 = (4) r1c4 => -26 r1c4

Fine, if it does it for you (few) players here.

For others, even if familiar with AIC's, the solution is a riddle, especially in your first formulation.
This way of extending a chain with one elimination to one with 2 has a name, but i don't remember it.
For me it is less elegance than arrogance not to mention that. At least i would expect an underlined (2) r3c5.

And yes, i like more one move with the 26 pair, than your - let's say - one and a half move.