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Jul 26 VH

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ZeroAssoluto

Joined: 05 Feb 2017
Posts: 941
Location: Rimini, Italy

Posted: Tue Jul 25, 2017 10:17 pm Post subject: Jul 26 VH

Hi everyone,

Code:

+-----------------+-------------+---------------+
| 2 379 6 | 5 1479 49 | 13 137 8 |
| 4 79 1 | 8 79 3 | 6 2 5 |
| 8 5 37 | 17 6 2 | 139 4 79 |
+-----------------+-------------+---------------+
| 357 13478 23478 | 47 378 6 | 1459 179 2479 |
| 6 147 9 | 247 27 5 | 8 17 3 |
| 357 3478 23478 | 9 378 1 | 45 6 247 |
+-----------------+-------------+---------------+
| 79 2 478 | 6 5 49 | 349 389 1 |
| 1 48 5 | 3 49 7 | 2 89 6 |
| 39 6 34 | 12 12 8 | 7 5 49 |
+-----------------+-------------+---------------+

Play this puzzle online at the Daily Sudoku site

Quote:

W-Wing 4,9 in r7c6, r9c9 connected by number 9 in r8c58 and -4 in r7c7
or
XY-Wing 4,8,9 in r8c28, r9c9 and -4 in r9c3

Ciao Gianni

Marty R.

Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

Posted: Wed Jul 26, 2017 5:12 am Post subject:

Code:

+-----------------+-------------+---------------+
| 2 379 6 | 5 1479 49 | 13 137 8 |
| 4 79 1 | 8 79 3 | 6 2 5 |
| 8 5 37 | 17 6 2 | 139 4 79 |
+-----------------+-------------+---------------+
| 357 13478 23478 | 47 38 6 | 1459 179 2479 |
| 6 147 9 | 247 27 5 | 8 17 3 |
| 357 3478 23478 | 9 38 1 | 45 6 247 |
+-----------------+-------------+---------------+
| 79 2 478 | 6 5 49 | 349 389 1 |
| 1 48 5 | 3 49 7 | 2 89 6 |
| 39 6 34 | 12 12 8 | 7 5 49 |
+-----------------+-------------+---------------+

Play this puzzle online at the Daily Sudoku site

I didn't see the other moves, so I played a 49 M-wing

(9=4)r7c6-r7c7=(4-9)r9c9 =r9c1=> -9r7c1

Ajò Dimonios

Joined: 01 May 2017
Posts: 339
Location: Sassari Italy

Posted: Wed Jul 26, 2017 7:06 am Post subject:

Hi everyone

Code:

+-----------------+-------------+---------------+
| 2 379 6 | 5 1479 49 | 13 137 8 |
| 4 79 1 | 8 79 3 | 6 2 5 |
| 8 5 37 | 17 6 2 | 139 4 79 |
+-----------------+-------------+---------------+
| 357 13478 23478 | 47 38 6 | 1459 179 2479 |
| 6 147 9 | 247 27 5 | 8 17 3 |
| 357 3478 23478 | 9 38 1 | 45 6 247 |
+-----------------+-------------+---------------+
| 79 2 478 | 6 5 49 | 349 389 1 |
| 1 48 5 | 3 49 7 | 2 89 6 |
| 39 6 34 | 12 12 8 | 7 5 49 |
+-----------------+-------------+---------------+

Play this puzzle online at the Daily Sudoku site
Forcing chain [(3-4)R7C7=(4)R9C9-(4)R9C3 and (3)R7C7-(3)R3C7=(3)R3C3-(3)R9C3 ]=>-contradiction R9C3=Ø=>-3R7C7 => stte.
Ciao a tutti
Paolo

Marty R.

Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

Posted: Wed Jul 26, 2017 2:48 pm Post subject:

Ajò Dimonios wrote:

Hi everyone

Code:

+-----------------+-------------+---------------+
| 2 379 6 | 5 1479 49 | 13 137 8 |
| 4 79 1 | 8 79 3 | 6 2 5 |
| 8 5 37 | 17 6 2 | 139 4 79 |
+-----------------+-------------+---------------+
| 357 13478 23478 | 47 38 6 | 1459 179 2479 |
| 6 147 9 | 247 27 5 | 8 17 3 |
| 357 3478 23478 | 9 38 1 | 45 6 247 |
+-----------------+-------------+---------------+
| 79 2 478 | 6 5 49 | 349 389 1 |
| 1 48 5 | 3 49 7 | 2 89 6 |
| 39 6 34 | 12 12 8 | 7 5 49 |
+-----------------+-------------+---------------+

Play this puzzle online at the Daily Sudoku site
Forcing chain [(3-4)R7C7=(4)R9C9-(4)R9C3 and (3)R7C7-(3)R3C7=(3)R3C3-(3)R9C3 ]=>-contradiction R9C3=Ø=>-3R7C7 => stte.
Ciao a tutti
Paolo

I don't understand why there's a contradiction. The first half of the notation ends without showing what happens if r9c3 is not 4 and the same with the second half with r9c3 not 3. I don't see any conclusion from which one can say there's a contradiction. I'm used to seeing chains end with one or more cells being <> or = to some value.

Ajò Dimonios

Joined: 01 May 2017
Posts: 339
Location: Sassari Italy

Posted: Wed Jul 26, 2017 4:17 pm Post subject:

Hi everyone

Marty wrote:

Quote:

Within the square brackets there are two chains that start both from the same initial hypothesis R7C7 = 3. The logical result of the first is that if R7C7 is equal to 3 then R9C3 <>4, the logical result of the second is that if R7C7 is equal to 3 then R9C3 <>3. At this point, the contradiction is created because no number can be placed in the R9C3 cell. The consequence of this reasoning is that the initial hypothesis (R7C7 = 3) is false. Eliminating the 3 in R7C7 easily resolves the puzzle.

Ciao a Tutti
Paolo

Marty R.

Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

Posted: Wed Jul 26, 2017 8:46 pm Post subject:

Code:

+-----------------+-------------+---------------+
| 2 379 6 | 5 1479 49 | 13 137 8 |
| 4 79 1 | 8 79 3 | 6 2 5 |
| 8 5 37 | 17 6 2 | 139 4 79 |
+-----------------+-------------+---------------+
| 357 13478 23478 | 47 38 6 | 1459 179 2479 |
| 6 147 9 | 247 27 5 | 8 17 3 |
| 357 3478 23478 | 9 38 1 | 45 6 247 |
+-----------------+-------------+---------------+
| 79 2 478 | 6 5 49 | 349 389 1 |
| 1 48 5 | 3 49 7 | 2 89 6 |
| 39 6 34 | 12 12 8 | 7 5 49 |
+-----------------+-------------+---------------+

Sorry, I'm not used to the notation. I'd be more comfortable with something like this:

[3r7c7-r3c7=r3c3-(3=4)r9c3 and 3r7c7-(3=894)r78c8r9c9-(4=3)r9c3 contradiction, r9c3=0=> -3r7c7]

Ajò Dimonios

Joined: 01 May 2017
Posts: 339
Location: Sassari Italy

Posted: Wed Jul 26, 2017 9:28 pm Post subject:

Hi Marty Ok, the result is similar. In one case it is proved that both numbers 3 and 4 are false in cell R9C3 (contradiction) and in the other demonstration that at the same time in cell R9C3 are certain 4 and 3 (contradiction). Ciao a tutti Paolo

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