February 26, 2017

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February 26, 2017

Postby ArkieTech » Sun Feb 26, 2017 12:40 am

Code: Select all
 *-----------*
 |..5|..4|..2|
 |.6.|...|.7.|
 |1..|.8.|5..|
 |---+---+---|
 |...|6.2|..3|
 |..7|...|9..|
 |4..|5.8|...|
 |---+---+---|
 |..9|.1.|..7|
 |.3.|...|.6.|
 |7..|8..|4..|
 *-----------*


Play/Print this puzzle online
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Re: February 26, 2017

Postby Leren » Sun Feb 26, 2017 1:08 am

Code: Select all
*--------------------------------------------------------------------------------*
| 39      78      5        | 1379    6       4        | 138     1389    2        |
| 39      6      b28       |c1239    35      1359e    | 138D    7       4        |
| 1       47     a4-2aA    | 2379    8       379      | 5       39      6        |
|--------------------------+--------------------------+--------------------------|
| 58      158     18       | 6       9       2        | 7       4       3        |
| 6       2       7        | 134     34      13       | 9       58      58       |
| 4       9       3        | 5       7       8        | 6       2       1        |
|--------------------------+--------------------------+--------------------------|
| 258     458     9        | 34      1       6        | 238     358     7        |
| 258     3       148bB    | 479     45c     579d     | 128C    6       589      |
| 7       15      6        | 8       2       359d     | 4       135     59       |
*--------------------------------------------------------------------------------*

Kraken Row 2 Digit 1:   

2 r3c3 - r2c3 = r2c4                                 - 1 r2c4;

2 r3c3 - 4 r3c3 = r8c3 - (4=5) r8c5 - r89c6 = 5 r2c6 - 1 r2c6;

2 r3c3 - 4 r3c3 = (4-1) r8c3 = r8c7                  - 1 r2c7; => - 2 r3c3; stte

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Re: February 26, 2017

Postby SteveG48 » Sun Feb 26, 2017 1:29 am

Code: Select all
 *-----------------------------------------------------------*
 | 39    78    5     | 1379  6     4     | 138   1389  2     |
 | 39    6    c2-8   | 1239 c35    1359  |d138   7     4     |
 | 1     47  bc24    | 2379  8     379   | 5     39    6     |
 *-------------------+-------------------+-------------------|
 | 58    158 af18    | 6     9     2     | 7     4     3     |
 | 6     2     7     | 134   34    13    | 9     58    58    |
 | 4     9     3     | 5     7     8     | 6     2     1     |
 *-------------------+-------------------+-------------------|
 | 258   458   9     | 34    1     6     | 238   358   7     |
 | 258   3   af148   | 479 bc45    579   |e128   6     589   |
 | 7     15    6     | 8     2     359   | 4     135   59    |
 *-----------------------------------------------------------*


(8=14)r48c3 - (4r3c3)|(4r8c5) = ((35)r28c5)&((28)r23c3) - (3|8=1)r2c7 - r8c7 = (18)r48c3 => -8 r2c3 ; stte
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Re: February 26, 2017

Postby Alex_Popov_92 » Sun Feb 26, 2017 6:51 am

In all my diagrams small digit in green means that
number is set in the cell. Small digit in red (or rather pink)
means that number is not present to the cell. Green
arrows lead to small green numbers. Red arrows lead to
small red numbers. (removed from the cell)
Code: Select all
 39   78   5    | 1379 6    4    | 138  1389 2   
 39   6    28   | 1239 35   1359 | 138  7    4   
 1    47   24   | 2379 8    379  | 5    39   6   
----------------+----------------+----------------
 58   158  18   | 6    9    2    | 7    4    3   
 6    2    7    | 134  34   13   | 9    58   58 
 4    9    3    | 5    7    8    | 6    2    1   
----------------+----------------+----------------
 258  458  9    | 34   1    6    | 238  358  7   
 258  3    148  | 479  45   579  | 128  6    589
 7    15   6    | 8    2    359  | 4    135  59 

Press the link to see the diagram
https://cloud.mail.ru/public/9Bz8/nUTSkHZPG
Let's assume that r9c6=3. Then
r7c4=4, r8c5=5, r2c5=3 => r3c4<>3, r3c6<>3
From r7c4=4 => r8c4 <> 4
From r8c5=5 => r8c6<> 5
In row 8 it only remains one cell for 4, r8c3=4
If r8c3=4 then r3c3=2, => r3c4<>2.
Now please see the diagram. The yellow cells
contain only digits 7 and 9. We got the
Deadly pattern and have two solutions.
So the assumption is wrong and r9c6<>3.
Thus only hidden singles remain.
Last edited by Alex_Popov_92 on Sun Feb 26, 2017 6:03 pm, edited 1 time in total.
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Re: February 26, 2017

Postby Alex_Popov_92 » Sun Feb 26, 2017 9:03 am

Code: Select all
 39   78   5    | 1379 6    4    | 138  1389 2   
 39   6    28   | 1239 35   1359 | 138  7    4   
 1    47   24   | 2379 8    379  | 5    39   6   
----------------+----------------+----------------
 58   158  18   | 6    9    2    | 7    4    3   
 6    2    7    | 134  34   13   | 9    58   58 
 4    9    3    | 5    7    8    | 6    2    1   
----------------+----------------+----------------
 258  458  9    | 34   1    6    | 238  358  7   
 258  3    148  | 479  45   579  | 128  6    589
 7    15   6    | 8    2    359  | 4    135  59 


In all my diagrams a small digit in green means that the
number is set in the cell. Small digit in red (or rather pink)
means that the number is not present in the cell. Green
arrows lead to small green numbers. Red arrows lead to
small red numbers. (removed from the cell)
Please press the link to see the diagram.
https://cloud.mail.ru/public/DkqF/gao1tRmtQ

Let's assume r3c3=2. Then r2c3=8 and
r2c7<>8.
r4c3=1 then r8c3<>1, r8c7=1 and r2c7<>1
So it follows that r2c7=3. r2c5=5, r8c5=4,
r8c3<>4 and finally r3c3 = 4, that is, <> 2 as
it was assumed. So r3c3 <> 2 and this reduces
the sudoku to hidden singles.
Alex
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Re: February 26, 2017

Postby eleven » Sun Feb 26, 2017 10:29 am

Nice, but hard to follow.

The reason is, that you have to remember, what candidates have been set/eliminated in the past.
Of course you can copy the grid into a solver and set r9c6 to 3, and follow the steps, until the UR is left. But this is very near to say: "set cell x to a, and press the solve button, until it says contradiction, so you can eliminate x".
You have seen, that we try to write the move in one AIC line, where the next link is completeley independent from the links before. So you can follow the move going through the links without remembering the past ones.
If remembering alinkis needed (or an intermediate result is needed for the deduction), these links are extra marked, e.g. by a star, color or underline.
If it is not possible to do it in a line (3- or 4-way deductions), several lines are used like in the Kraken presentation, but each line with independent links. So you can follow it easily line by line.

This is a presentation of your move, which is (hopefully) accepted here.
Code: Select all
 39   78   5    |  1379  6    4    | 138  1389 2   
 39   6    28   |  1239 a35   1359 | 138  7    4   
 1    47  A24   | #79+23 8   #79+3 | 5    39   6   
----------------+------------------+----------------
 58   158  18   |  6     9    2    | 7    4    3   
 6    2    7    |  134   34   13   | 9    58   58
 4    9    3    |  5     7    8    | 6    2    1   
----------------+------------------+----------------
 258  458  9    |Db34    1    6    | 238  358  7   
 258  3   B148  |C#479 Cb45  #579  | 128  6    589
 7    15   6    |  8     2    35*9 | 4    135  59

UR 79r38c46:
(Note that 9r9c6 is an "external" UR candidate, if it is missing, there is a hidden pair 79 in that box. For box 2 the "internal" extra candidates 23 are taken. So one of these candidates must be true, called a Strong Inference Set.)
SIS(9r9c6,3r3c6,23r3c4)
9r9c6 - 3r9c6
3r3c6 - 3r9c6
3r3c4 - (3=5)-(5=3)r8c5,r7c3 - 3r9c6
2r3c4 - (2=4)r3c3-r8c3=r8c45-(4=3)r7c4 - 3r9c6
=> r9c6<>3, stte


What you call "simulated" Sue de Coq (or whatever), is called "almost" Sue de Coq here (either r2c5<>5 or the Sue de Coq eliminations are true). btw i can't see your Sue deCoq.
[edit: typo]
Last edited by eleven on Sun Feb 26, 2017 12:05 pm, edited 1 time in total.
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Re: February 26, 2017

Postby eleven » Sun Feb 26, 2017 10:30 am

Code: Select all
 *-------------------------------------------------------*
 |  39     78   5    | 1379  6   4     | 138  1389  2    |
 |  39     6   A28   | 1239  35  1359  | 138  7     4    |
 |  1      47  A24   | 2379  8   379   | 5    39    6    |
 |-------------------+-----------------+-----------------|
 | #58    #158  1*8  | 6     9   2     | 7    4     3    |
 |  6      2    7    | 134   34  13    | 9    58    58   |
 |  4      9    3    | 5     7   8     | 6    2     1    |
 |-------------------+-----------------+-----------------|
 |e#58+2 e#58+4 9    | 34    1   6     |a238  358   7    |
 | e258    3    18-4 | 479   45  579   |b128  6     589  |
 |  7     d15   6    | 8     2   359   | 4   c135   59   |
 *-------------------------------------------------------*

UR 58r47c12: SIS (8r4c3, 2r7c1, 4r7c2)
8r4c3-(8=4)r23c3 - 4r8c3
2r7c1-r7c7=(2-1)r8c7=r9c8-(1=5)r9c2-(5=4)b7p124 - 4r8c3
4r7c2 - 4r8c3
=> r8c3<>4, stte
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Re: February 26, 2017

Postby Cenoman » Sun Feb 26, 2017 10:39 am

Code: Select all
 +-------------------+--------------------+--------------------+
 | 39    78    5     | 1379   6    4      | 138   1389   2     |
 | 39    6     28    | 1239  f35   1359   | 138   7      4     |
 | 1     47    24    |e2379   8   e379    | 5    d39     6     |
 +-------------------+--------------------+--------------------+
 | 58    158   18    | 6      9    2      | 7     4      3     |
 | 6     2     7     | 134    34   13     | 9    c58     58    |
 | 4     9     3     | 5      7    8      | 6     2      1     |
 +-------------------+--------------------+--------------------+
 | 258   458   9     | 34     1    6      | 238  c358    7     |
 | 258   3    a18-4  | 479   f45   579    | 128   6      589   |
 | 7    b15    6     | 8      2    359    | 4    c135    59    |
 +-------------------+--------------------+--------------------+

(1)r8c3 = r9c2 - (1=3)r589c8 - r3c8 = r3c46 - (3=4)r28c5 => -4 r8c3; stte

Edit: ...(3=4)r28c45 replaced with ...(3=4)r28c5 (typo spotted by SteveG48)

Cenoman
Last edited by Cenoman on Sun Feb 26, 2017 6:34 pm, edited 1 time in total.
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Re: February 26, 2017

Postby pjb » Sun Feb 26, 2017 11:16 am

Code: Select all
 39      78      5      | 1379   6      4      | 138    1389   2     
 39      6      b28     |a1239  B35    A1359   | 138a   7      4     
 1       47     c24     | 2379   8      379    | 5      39     6     
------------------------+----------------------+---------------------
 58      158     18     | 6      9      2      | 7      4      3     
 6       2       7      | 134    34     13     | 9      58     58     
 4       9       3      | 5      7      8      | 6      2      1     
------------------------+----------------------+---------------------
 258     458     9      | 34     1      6      | 238    358    7     
 258     3     dD148c   | 479   C45     579    | 128b   6      589   
 7       15      6      | 8      2      359    | 4      135    59     

(1-2)r2c4 = r2c3 - (2=4)r3c3 - 4 r8c3
(1-5)r2c6 = r2c5 - (5=4)r8c5 - 4 r8c3
(1)r2c7 - r8c7 = (1-4)r8c3 => -4 r8c3; stte

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Re: February 26, 2017

Postby eleven » Sun Feb 26, 2017 1:46 pm

Alex_Popov_92 wrote:https://cloud.mail.ru/public/DkqF/gao1tRmtQ
Let's assume r3c3=2. ...

Alex,

there is definitely no sense in flooding the forum with more or less complex network diagrams.
This one is from Sudoku Explainer, a program which is 11 years old now.
Do you have fun reading it and follwing the steps
"Let's assume r4c2=1 ... bla bla" ?
Attachments
SudokuExplainer.jpg
SudokuExplainer.jpg (46.98 KiB) Viewed 132 times
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Re: February 26, 2017

Postby SteveG48 » Sun Feb 26, 2017 2:46 pm

Cenoman wrote:
Code: Select all
 +-------------------+--------------------+--------------------+
 | 39    78    5     | 1379   6    4      | 138   1389   2     |
 | 39    6     28    | 1239  f35   1359   | 138   7      4     |
 | 1     47    24    |e2379   8   e379    | 5    d39     6     |
 +-------------------+--------------------+--------------------+
 | 58    158   18    | 6      9    2      | 7     4      3     |
 | 6     2     7     | 134    34   13     | 9    c58     58    |
 | 4     9     3     | 5      7    8      | 6     2      1     |
 +-------------------+--------------------+--------------------+
 | 258   458   9     | 34     1    6      | 238  c358    7     |
 | 258   3    a18-4  | 479   f45   579    | 128   6      589   |
 | 7    b15    6     | 8      2    359    | 4    c135    59    |
 +-------------------+--------------------+--------------------+

(1)r8c3 = r9c2 - (1=3)r589c8 - r3c8 = r3c46 - (3=4)r28c45 => -4 r8c3; stte

Cenoman


Nice one, Big C. I think the highlighted 4 is a typo.
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Re: February 26, 2017

Postby Alex_Popov_92 » Sun Feb 26, 2017 2:48 pm

I am really sorry, Eleven. You have rules, I don't comply.
Thank you all guys.
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Re: February 26, 2017

Postby SteveG48 » Sun Feb 26, 2017 3:06 pm

Alex_Popov_92 wrote:I am really sorry, Eleven. You have rules, I don't comply.
Thank you all guys.


Don't be discouraged, Alex. You're a good solver. You'll soon get the hang of the notation, and then it will be easy to present your solutions.
Steve
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Re: February 26, 2017

Postby bat999 » Sun Feb 26, 2017 3:19 pm

SteveG48 wrote:... get the hang of the notation...

Yes, I had a lot of trouble with the Eureka notation.
Using mathematical symbols - and = to do something non-mathematical.
Now I think...
- is a weak link, just a prod with one little finger. So weak it can only switch something off.
= is a strong link, a hefty push with both arms. So strong it can switch something on.
:)
8-)
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Re: February 26, 2017

Postby eleven » Sun Feb 26, 2017 3:30 pm

bat999 wrote:Yes, I had a lot of trouble with the Eureka notation.

Another trouble is that relatively easy things look that complicated.
When you look at Steve's solution:
Code: Select all
 *-----------------------------------------------------------*
 | 39    78    5     | 1379  6     4     | 138   1389  2     |
 | 39    6    c2-8   | 1239 c35    1359  |d138   7     4     |
 | 1     47  bc24    | 2379  8     379   | 5     39    6     |
 *-------------------+-------------------+-------------------|
 | 58    158 af18    | 6     9     2     | 7     4     3     |
 | 6     2     7     | 134   34    13    | 9     58    58    |
 | 4     9     3     | 5     7     8     | 6     2     1     |
 *-------------------+-------------------+-------------------|
 | 258   458   9     | 34    1     6     | 238   358   7     |
 | 258   3   af148   | 479 bc45    579   |e128   6     589   |
 | 7     15    6     | 8     2     359   | 4     135   59    |
 *-----------------------------------------------------------*

it is easy to spot:
(8=4)r48c3, then 5r8c5 (last digit) and 1r8c7 (last 1 in row) - (5|1=8)r2c57 => -8r2c3,
but hard to formulate.
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