dailysudoku.com :: View topic

dailysudoku.com
Discussion of Daily Sudoku puzzles

FAQ

Memberlist

Usergroups

Profile

Jul 26 VH

dailysudoku.com Forum Index -> Daily Sudoku puzzles

View previous topic :: View next topic

Author

Message

ZeroAssoluto

Joined: 05 Feb 2017
Posts: 1019
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

Display posts from previous:

	dailysudoku.com Forum Index -> Daily Sudoku puzzles	All times are GMT
Page 1 of 1

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum