The New Sudoku Players' Forum

[ArkieTech]

Code: Select all

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


Play/Print this puzzle online

[Leren]

Code: Select all

*---------------------------------------------------------------*
| 6     8     9      | 7     2     4      | 1     3      5      |
| 3     4     15     | 58    16    68     | 7     9      2      |
| 57    17    2      | 59    19    3      | 8     46     46     |
|--------------------+--------------------+---------------------|
| 2     9     15     | 6     47    78     | 3     15     48     |
| 57    1367  67     |c238   34    9      | 45    12456 d48-6   |
| 4     36    8      |b23    5     1      | 9    a26     7      |
|--------------------+--------------------+---------------------|
| 1     2     3      | 4     8     5      | 6     7      9      |
| 9     5     4      | 1     67    67     | 2     8      3      |
| 8     67    67     | 39    39    2      | 45    45     1      |
*---------------------------------------------------------------*

H2 Wing: (6=2) r6c8 - r6c4 = (2-8) r5c4 = (8) r5c9 => - 6 r5c9; stte

Leren

[Marty R.]

Code: Select all

+------------+-----------+--------------+
| 6  8    9  | 7   2  4  | 1  3     5   |
| 3  4    15 | 58  16 68 | 7  9     2   |
| 57 17   2  | 59  19 3  | 8  46    46  |
+------------+-----------+--------------+
| 2  9    15 | 6   47 78 | 3  15    48  |
| 57 1367 67 | 238 34 9  | 45 12456 468 |
| 4  36   8  | 23  5  1  | 9  26    7   |
+------------+-----------+--------------+
| 1  2    3  | 4   8  5  | 6  7     9   |
| 9  5    4  | 1   67 67 | 2  8     3   |
| 8  67   67 | 39  39 2  | 45 45    1   |
+------------+-----------+--------------+


Play this puzzle online at the Daily Sudoku site

Coloring (6), Kite hinged in b4 and extended: if Leren or Steve would like to check my notation, I'm not sure about terms 2-3 trying to establish the kite.
(6=236)r6c842-r5c3=r9c3-(6=75)b4p64-r3c1=r2c3-(5=8)r2c4--r2c6=r4c6-(8=4)r4c9-(4=6)r3c9=> -6r4c8

[SteveG48]

Code: Select all

 *--------------------------------------------------------------------*
 | 6      8      9      | 7      2      4      | 1      3      5      |
 | 3      4      15     | 58     16     68     | 7      9      2      |
 | 57     17     2      | 59     19     3      | 8      46     46     |
 *----------------------+----------------------+----------------------|
 | 2      9      15     | 6      47     78     | 3      15     48     |
 |a57     167-3 a67     | 238   a34     9      |a45     12456  468    |
 | 4     b36     8      | 2-3    5      1      | 9      26     7      |
 *----------------------+----------------------+----------------------|
 | 1      2      3      | 4      8      5      | 6      7      9      |
 | 9      5      4      | 1      67     67     | 2      8      3      |
 | 8      67     67     | 39     39     2      | 45     45     1      |
 *--------------------------------------------------------------------*


(3=4567)r5c1357 - (6=3)r6c2 => -3 r5c2,r6c4 ; stte

[SteveG48]

Code: Select all

+------------+-----------+--------------+
| 6  8    9  | 7   2  4  | 1  3     5   |
| 3  4    15 | 58  16 68 | 7  9     2   |
| 57 17   2  | 59  19 3  | 8  46    46  |
+------------+-----------+--------------+
| 2  9    15 | 6   47 78 | 3  15    48  |
| 57 1367 67 | 238 34 9  | 45 12456 468 |
| 4  36   8  | 23  5  1  | 9  26    7   |
+------------+-----------+--------------+
| 1  2    3  | 4   8  5  | 6  7     9   |
| 9  5    4  | 1   67 67 | 2  8     3   |
| 8  67   67 | 39  39 2  | 45 45    1   |
+------------+-----------+--------------+


Play this puzzle online at the Daily Sudoku site

Coloring (6), Kite hinged in b4 and extended: if Leren or Steve would like to check my notation, I'm not sure about terms 2-3 trying to establish the kite.
(6=236)r6c842-r5c3=r9c3-(6=75)b4p64-r3c1=r2c3-(5=8)r2c4--r2c6=r4c6-(8=4)r4c9-(4=6)r3c9=> -6r4c8

Hi, Marty. First, I think your conclusion was meant to be -6 r3c8, not -6 r4c8.

On the chain, the only error is in your first term. You can't have 6 on both sides of an = sign. That would mean that if 6 isn't true in that cell or group if cells then it is true in the cell- a contradiction. Break it into 2 pieces:

(6=2)r6c8 - (2=36)r6c24 - 6r5c3 ....

You could actually eliminate the -6r5c3 = r9c3 - (6=75)b4p46 and just write - (6=75)b4p46 without the first two terms, but that's not an error.

[Marty R.]

Code: Select all

+------------+-----------+--------------+
| 6  8    9  | 7   2  4  | 1  3     5   |
| 3  4    15 | 58  16 68 | 7  9     2   |
| 57 17   2  | 59  19 3  | 8  46    46  |
+------------+-----------+--------------+
| 2  9    15 | 6   47 78 | 3  15    48  |
| 57 1367 67 | 238 34 9  | 45 12456 468 |
| 4  36   8  | 23  5  1  | 9  26    7   |
+------------+-----------+--------------+
| 1  2    3  | 4   8  5  | 6  7     9   |
| 9  5    4  | 1   67 67 | 2  8     3   |
| 8  67   67 | 39  39 2  | 45 45    1   |
+------------+-----------+--------------+


Play this puzzle online at the Daily Sudoku site

Coloring (6), Kite hinged in b4 and extended: if Leren or Steve would like to check my notation, I'm not sure about terms 2-3 trying to establish the kite.
(6=236)r6c842-r5c3=r9c3-(6=75)b4p64-r3c1=r2c3-(5=8)r2c4--r2c6=r4c6-(8=4)r4c9-(4=6)r3c9=> -6r4c8

Hi, Marty. First, I think your conclusion was meant to be -6 r3c8, not -6 r4c8.

On the chain, the only error is in your first term. You can't have 6 on both sides of an = sign. That would mean that if 6 isn't true in that cell or group if cells then it is true in the cell- a contradiction. Break it into 2 pieces:

(6=2)r6c8 - (2=36)r6c24 - 6r5c3 ....

You could actually eliminate the -6r5c3 = r9c3 - (6=75)b4p46 and just write - (6=75)b4p46 without the first two terms, but that's not an error.

Steve,

Thanks a lot for checking the notation.

"On the chain, the only error is in your first term. You can't have 6 on both sides of an = sign. That would mean that if 6 isn't true in that cell or group if cells then it is true in the cell- a contradiction. Break it into 2 pieces:"

I should've known that. I was thinking that r6c8 isn't a 6 so r6c2 IS a 6.

I was going to just say that due to the Kite r6c8 and r9c3 are pincers and just take it from there. But then thought I'd try to get the full Kite in there. The way I actually did the puzzle was to start transporting with r9c3.

"You could actually eliminate the -6r5c3 = r9c3 - (6=75)b4p46 and just write - (6=75)b4p46 without the first two terms," This was the main reason I wanted the notation checked. It didn't seem right to go from r5c3 to r9c3 and right back to r5c3. By skipping that it wouldn't show the full kite with transport starting with r9c3.

[Cenoman]

A question to DP experts.

Code: Select all

 +-------------------+------------------+---------------------+
 |  6    8      9    |  7     2    4    |  1    3       5     |
 |  3    4      15   |  58    16   68   |  7    9       2     |
 |  57   17     2    |  59    19   3    |  8   *46     *46    |
 +-------------------+------------------+---------------------+
 |  2    9      15   |  6     47   78   |  3    15      48    |
 |  57   1367   67   |  238   34   9    | *45  *12456  *468   |
 |  4    36     8    |  23    5    1    |  9    26      7     |
 +-------------------+------------------+---------------------+
 |  1    2      3    |  4     8    5    |  6    7       9     |
 |  9    5      4    |  1     67   67   |  2    8       3     |
 |  8    67     67   |  39    39   2    | *45  *45      1     |
 +-------------------+------------------+---------------------+

Are the seven cells tagged with "*", a deadly pattern with digits 4, 5, 6 ?

Thanks in advance.
Cenoman.

[bat999]

Code: Select all

.---------------.---------------.--------------------.
| 6    8     9  |  7     2   4  | 1     3        5   |
| 3    4     15 |  58    16  68 | 7     9        2   |
| 57  b17    2  |  59   b19  3  | 8     46       46  |
:---------------+---------------+--------------------:
| 2    9     15 |  6     47  78 | 3     15      c48  |
| 57   1367  67 |  238  a34  9  | 5-4   1256-4  c468 |
| 4   b36    8  | c23    5   1  | 9    c26       7   |
:---------------+---------------+--------------------:
| 1    2     3  |  4     8   5  | 6     7        9   |
| 9    5     4  |  1     67  67 | 2     8        3   |
| 8   b67    67 |  39   a39  2  | 45    45       1   |
'---------------'---------------'--------------------'

(4=9)r59c5 - (9=3)r369c2,r3c5 - (3=4)r45c9,r6c48 => -4 r5c78; stte

[Leren]

Cenoman wrote : Are the seven cells tagged with "*", a deadly pattern with digits 4, 5, 6 ?

I'd say the answer is yes. It's like two 4 cell DP's; one in digits 46 and one in digits 45 that have a common cell r5c8.

If you pick r3c8 = 4 and r3c9 = 6 you are forced into a 4 cell 46 DP in r35c89. On the other hand if you pick r3c8 = 6 and r3c9 = 4 you are forced into either a 4 cell 64 DP in r35c89 or a 4 cell 45 DP in r59c78.

In fact you can eliminate 45 from r5c8 straight away, as there are 3 cells with just 45 in r59c78. BTW there is also a 4 cell 67 DP in r59c23 so you can remove 67 from r5c2.

So I guess you are just left with a 46 DP in r45c89, so either r5c8 is 12 or r5c9 is 8.

You can learn a lot about all sorts of exotic DP's here.

Leren

[Ngisa]

Code: Select all

+------------+-----------+--------------+
| 6  8    9  | 7   2  4  | 1  3     5   |
| 3  4    c15 | 58  b16 68 | 7  9     2   |
| d57 17   2  | 59  19 3  | 8  46    46  |
+------------+-----------+--------------+
| 2  9    15 | 6   a47 78 | 3  15-4   8-4  |
| e57 1367 67 | 238 3-4 9  | f54 12456 468 |
| 4  36   8  | 23  5  1  | 9  26    7   |
+------------+-----------+--------------+
| 1  2    3  | 4   8  5  | 6  7     9   |
| 9  5    4  | 1   b67 67 | 2  8     3   |
| 8  67   67 | 39  39 2  | 45 45    1   |
+------------+-----------+--------------+


(4=7)r4c5 - (7=1)r28c5 - (1=5)r2c3 - (5=7)r3c1 - (7=5)r5c1 - (5=4)r5c7 => - 4 r4c89, r5c5; stte

Clement

[Sudtyro2]

Code: Select all

*----------------------------------------------------------*
| 6      8      9    | 7      2    4    |  1   3      5    |
| 3      4      15   | 58     16   68   |  7   9      2    |
| 57     17     2    | 59     19   3    |  8   46     46   |
|--------------------+------------------+------------------|
| 2      9      5-1  | 6      47   78   |  3  c15     48   |
| 57    a1367*  67*  | 238   b34   9    | c45  12456  468  |
| 4      36     8    | 23     5    1    |  9   26     7    |
|--------------------+------------------+------------------|
| 1      2      3    | 4      8    5    |  6   7      9    |
| 9      5      4    | 1      67   67   |  2   8      3    |
| 8      67*    67*  | 39     39   2    |  45  45     1    |
*----------------------------------------------------------*

ADP(67)r59c23, using internals.
[1=3]r5c2 - (3=4)r5c5 - (4=51)b6p24 => -1r4c3; stte
SteveC

[Cenoman]

Leren wrote: I'd say the answer is yes

So was my own feeling. Thanks Leren, especially for the link. I had only this link http://sudopedia.enjoysudoku.com/Deadly_Pattern.html dealing with most frequent DP's and was in trouble with the 3rd criterion defining a DP.
For today's puzzle, the DP would yield the following path:

Code: Select all

 +-------------------+------------------+---------------------+
 |  6    8      9    |  7     2    4    |  1    3       5     |
 |  3    4      15   |  58    16   68   |  7    9       2     |
 |  57   17     2    |  59    19   3    |  8   *4-6    *46    |
 +-------------------+------------------+---------------------+
 |  2    9      15   |  6     47  c78   |  3   a15    Ab48    |
 |  57   1367   67   | d238   34   9    |*b45  *12456  *468   |
 |  4    36     8    | e23    5    1    |  9   f26      7     |
 +-------------------+------------------+---------------------+
 |  1    2      3    |  4     8    5    |  6    7       9     |
 |  9    5      4    |  1     67   67   |  2    8       3     |
 |  8    67     67   |  39    39   2    | *45  *45      1     |
 +-------------------+------------------+---------------------+

DP(456)r3c89, r5c789, r9c78 using externals (box 6) => -6 r3c8; stte

Code: Select all

(5)r4c8 - (5=8)b7p34 - r4c6 = (8-2)r5c4 = r6c4 - (2=6)r6c8 - 6r3c8
(4)r4c9 - (4=6)r3c9                                        - 6r3c8
(6)r6c8                                                    - 6r3c8

Congratulations to SteveC for his nice UR !

Cenoman