The New Sudoku Players' Forum

[ArkieTech]

Code: Select all

 *-----------*
 |.2.|1..|.9.|
 |3..|.4.|..8|
 |..6|...|2..|
 |---+---+---|
 |5..|7.3|.8.|
 |...|.1.|...|
 |.1.|4.6|..9|
 |---+---+---|
 |..8|...|9..|
 |7..|.5.|..3|
 |.4.|..1|.6.|
 *-----------*


Play/Print this puzzle online

[Cenoman]

Code: Select all

 +------------------------+------------------------+-------------------------+
 |  48      2     457     |  1      3678    578    |  3567   9       567     |
 |  3       57    19      |  2569   4       2579   |  1567   157     8       |
 | a19      578   6       |  3589   3789    5789   |  2      13457   1457    |
 +------------------------+------------------------+-------------------------+
 |  5       69    249     |  7      29      3      |  146    8       1246    |
 |  4689-2  378   23479   |  2589   1       2589   |  3467   2347    2467    |
 |  8-2     1     37      |  4      28      6      |  357    357     9       |
 +------------------------+------------------------+-------------------------+
 | a126     35    8       |  236    2367    247    |  9      12457   12457   |
 |  7      b69    19-2    |  2689   5       2489   |  148    124     3       |
 |ba29      4     35      |  2389   23789   1      |  578    6       257     |
 +------------------------+------------------------+-------------------------+

(2=196)r379c1 - (6=92)b7p57 => -2 r56c1, r8c3; ste (ste from -2r6c1 alone)

[SpAce]

Code: Select all

.------------------------.-------------------.--------------------.
| c(48)       2    457   | 1     3678   578  | 3567  9      567   |
|   3         57   19    | 2569  4      2579 | 1567  157    8     |
|   19        578  6     | 3589  3789   5789 | 2     13457  1457  |
:------------------------+-------------------+--------------------:
|   5         69   249   | 7     29     3    | 146   8      1246  |
| a[6]9-248   378  23479 | 2589  1      2589 | 3467  2347   2467  |
| c(28)       1    37    | 4     28     6    | 357   357    9     |
:------------------------+-------------------+--------------------:
|  b126       35   8     | 236   2367   247  | 9     12457  12457 |
|   7        b69   129   | 2689  5      2489 | 148   124    3     |
| c(2)9       4    35    | 2389  23789  1    | 578   6      257   |
'------------------------'-------------------'--------------------'

(6)r5c1 = (69)b7p15 - (9=284)r961c1 => -248 r5c1; stte

[SteveG48]

I neglected to do the basics, and got this:

Code: Select all

 *--------------------------------------------------------------------*
 | 48     2      457    | 1      3678   578    | 34567  9      4567   |
 | 3     d579   d1579   | 2569   4      2579   | 1567   157    8      |
 |c1489  d5789   6      | 3589   3789   5789   | 2      13457  1457   |
 *----------------------+----------------------+----------------------|
 | 5      6-9    249    | 7     a29     3      | 146    8      1246   |
 | 24689  36789  23479  | 2589   1      2589   | 34567  23457  24567  |
 |b28     1      237    | 4     a28     6      | 357    2357   9      |
 *----------------------+----------------------+----------------------|
 |b126    356    8      | 236    2367   247    | 9      12457  12457  |
 | 7     a69     129    | 2689   5      2489   | 148    124    3      |
 |b29     4      2359   | 2389   23789  1      | 578    6      257    |
 *--------------------------------------------------------------------*


(9=268)r46c5,r8c2 - (6|8=129)r679c1 - (1|9)r3c1 = (19)b1p568 => -9 r4c2 ; stte

[Ngisa]

Code: Select all

+-----------------------+-----------------------+------------------------+
| 48       2      457   | 1       3678     578  | 3567    9        567   |
| 3        57    c19    | 2569    4        2579 | 1567    157      8     |
|d19       578    6     | 3589    3789     5789 | 2       13457    1457  |
+-----------------------+-----------------------+------------------------+
| 5        69    a249   | 7       29       3    | 146     8        1246  |
| 24689    378   a23479 | 2589    1        2589 | 3467    2347     2467  |
| 8-2      1      37    | 4       28       6    | 357     357      9     |
+-----------------------+-----------------------+------------------------+
| 126      35     8     | 236     2367     247  | 9       12457    12457 |
| 7        69    b129   | 2689    5        2489 | 148     124      3     |
|e29       4      35    | 2389    23789    1    | 578     6        257   |
+-----------------------+-----------------------+------------------------+


(2)r45c3 = (2-1)r8c3 = (1-9)r2c3 = r3c1 - (9=2)r9c1 => - 2r6c1; stte

Clement

[eleven]

(2=196)r379c1 - (6=92)b7p57 => -2 r56c1, r8c3; ste (ste from -2r6c1 alone)

It's a wxyz-wing: 1269 in 4 cells, only 9 can be twice (r3c1 and r8c2).
9r8c2 -> 2r9c1 => 2r79c1

[SpAce]

I neglected to do the basics, and got this:

(9=268)r46c5,r8c2 - (6|8=129)r679c1 - (1|9)r3c1 = (19)b1p568 => -9 r4c2 ; stte

Nice! It seems that my move is also available without doing basics, but only gives btte.

[SpAce]

Hi eleven,

(2=196)r379c1 - (6=92)b7p57 => -2 r56c1, r8c3; ste (ste from -2r6c1 alone)

It's a wxyz-wing: 1269 in 4 cells, only 9 can be twice (r3c1 and r8c2).
9r8c2 -> 2r9c1 => 2r79c1

I don't know what the truth is, but last time I offered a similar overlapping pattern as a WXYZ-Wing it got questioned! SudokuWiki doesn't recognize it as such either (not that it means much, but it's the only solver I know that has WXYZ-Wing). What is the actual definition?

[rjamil]

Hi SpAce and eleven,

Hi eleven,

(2=196)r379c1 - (6=92)b7p57 => -2 r56c1, r8c3; ste (ste from -2r6c1 alone)

It's a wxyz-wing: 1269 in 4 cells, only 9 can be twice (r3c1 and r8c2).
9r8c2 -> 2r9c1 => 2r79c1

I don't know what the truth is, but last time I offered a similar overlapping pattern as a WXYZ-Wing it got questioned! SudokuWiki doesn't recognize it as such either (not that it means much, but it's the only solver I know that has WXYZ-Wing). What is the actual definition?

Well, I also confirm that there is no WXYZ-Wing move found, as per StrmCkr defined patterns here.

R. Jamil

[eleven]

What is the actual definition?

First of all i don't mind who calls what a wxyz-wing and what not.
There is no official definition. It goes back to 2005/2006, that there are different opinions.

@Rjamil: StrCkr says in his "Collary" (probably corollary):
"WXYZ-Wings can be considered as a group of 4 cells and 4 digits, that has exactly one non-restricted common digit."
As i understand it, this would fit here for the 9.

Personally i use the definition, that all groups of 4 cells and 4 digits in a box plus a line, which eliminate outside digits, can be called wxyz-wings. At least that fits for all so-called wxyz-wings i saw.

[rjamil]

Hi eleven,

@Rjamil: StrCkr says in his "Collary" (probably corollary):
"WXYZ-Wings can be considered as a group of 4 cells and 4 digits, that has exactly one non-restricted common digit."
As i understand it, this would fit here for the 9.

Personally i use the definition, that all groups of 4 cells and 4 digits in a box plus a line, which eliminate outside digits, can be called wxyz-wings. At least that fits for all so-called wxyz-wings i saw.

If I am correct, then you are referring to the various patterns of BARNS=4 that are not covered in WXYZ-Wing move defined by StrmCkr.

I have not considered all of them as WXYZ-Wing move; otherwise there is confusion between BARNS=4 and WXYZ-Wing, i.e, see here and here.

Actually, the definition that I consider for WXYZ-Wing move is: either an apex or two apexes must see all wings.

R. Jamil

[eleven]

Maybe a good definition for programmers.

My view is, that when i see 4 digits in 4 cells in a box/line, i look, if it eliminates something. This is done rather quickly in most cases, if you look which digit can be twice.