The New Sudoku Players' Forum

[ArkieTech]

Code: Select all

 *-----------*
 |..5|1.8|..2|
 |..7|...|.3.|
 |.4.|..3|...|
 |---+---+---|
 |29.|...|5..|
 |...|.3.|...|
 |..1|...|.47|
 |---+---+---|
 |...|2..|.1.|
 |.7.|...|6..|
 |8..|5.6|9..|
 *-----------*


Play/Print this puzzle online

[storm_norm22]

x-wing on 3; r7c39 <> 3
skyscraper on 4; r7c7 and r2c9 <> 4
kite on 7; r3c8 <> 7

brings up this grid

Code: Select all

.------------------.------------------.------------------.
| 369   36    5    | 1     4679  8    | 47    679   2    |
| 169   2     7    | 469   4569  459  | 148   3     1689 |
| 169   4     8    | 679   2     3    | 17    569   1569 |
:------------------+------------------+------------------:
| 2     9     346  | 4678  1467  147  | 5     68    1368 |
| 7     568   46   | 468   3     1245 | 128   689   1689 |
| 356   3568  1    | 689   569   259  | 238   4     7    |
:------------------+------------------+------------------:
| 3456  356   69   | 2     4789  479  | 378   1     458  |
| 45    7     29   | 3     1489  149  | 6     258   458  |
| 8     1     23   | 5     47    6    | 9     27    34   |
'------------------'------------------'------------------'

(2=3)r9c3 - (3)r9c9 = (3-7)r7c7 = (7)r9c8; r9c8 <> 2

[ArkieTech]

Code: Select all

 *--------------------------------------------------------------------*
 | 369    36     5      | 1      4679   8      | 47     679    2      |
 | 169    2      7      | 469    4569   459    | 148    3      14689  |
 | 169    4      8      | 679    2      3      | 17     5679   1569   |
 |----------------------+----------------------+----------------------|
 | 2      9      346    | 4678   1467   147    | 5      68     1368   |
 | 7      568    46     | 468    3      1245   | 128    689    1689   |
 | 356    3568   1      | 689    569    259    | 238    4      7      |
 |----------------------+----------------------+----------------------|
 | 3456   356    369    | 2      4789   479    |d478-3  1      3458   |
 | 45     7      29     | 3      1489   149    | 6      258    458    |
 | 8      1      23     | 5     b47     6      | 9     c27    a34     |
 *--------------------------------------------------------------------*
H-wing
(3=4)r9c9-(4=7)r9c5-r9c8=7r7c7 = -3r7c7; stte

[tlanglet]

2r9c3=(2-7)r9c8=(7-3)r7c7=r6c7-r6c12=3r4c3 => r9c3<>3

Ted
{Question: Why is my font size so small?]

[eleven]

Either triple 458 in r789c9 -> r8c8=2
or r79c9=3 -> r4c3=3 -> r9c3=2
(2=58)r8c8-(458=3)r789c9-3r4c9=3r4c3-(3=2)r9c3 -> r8c3,r9c8<>2

What do you mean with small fonts ?

[tlanglet]

What do you mean with small fonts ?

Notice the various font sized in any post. The second line has a larger font than all of the remaining text. Also, the posts use a smaller font than all of the forum content. My old eyes would appreciate a larger font

[eleven]

Hm, i cant see that, neither in Firefox nor Internet Explorer. Also in both browsers you can enlarge the size by zooming in, either from the menu or by pressing both CTRL and +.

[Marty R.]

Code: Select all

+---------------+-----------------+--------------------+
| 369  36   5   | 1     4679 8    | B47    679   2     |
| 169  2    7   | 469   4569 459  | G148   3     14689 |
| 169  4    8   | 679   2    3    | A17   C5679  1569  |
+---------------+-----------------+--------------------+
| 2    9    346 | 4678  1467 147  |  5     68    1368  |
| 7    568  46  | 468   3    1245 |  128   689   1689  |
| 356  3568 1   | 689   569  259  |  238   4     7     |
+---------------+-----------------+--------------------+
| 3456 356  369 | 2     4789 479  | F3478  1     3458  |
| 45   7    29  | 3     1489 149  |  6     258   458   |
| 8    1    23  | 5    D47   6    |  9    C27   E34    |
+---------------+-----------------+--------------------+

Loop. R3c7=7=>r2c7=1. R7c7<>7. I don't know if my alphabet scheme makes sense and I can't even begin to notate it.

[eleven]

Interesting, but though i see the implications you call a loop here, in my opinion it does not allow you to eliminate the 7 in r7c7.

The problem is, that not every part of the loop alone implies the next one, e.g. r1c7=4 does not imply r13c8<>7 or r9c9=3 does not imply r7c7=8 (the loop is not built by a chain, but by a net).
So not only the loop digits or only their opposites can be valid for these cells.
For example your loop does not exclude those digits (left of the + sign).

Code: Select all

+---------------+-----------------+--------------------+
| 369  36   5   | 1     4679 8    | 4+7   69+7   2     |
| 169  2    7   | 469   4569 459  | 8+14   3     14689 |
| 169  4    8   | 679   2    3    | 1+7   7+569  1569  |
+---------------+-----------------+--------------------+
| 2    9    346 | 4678  1467 147  |  5     68    1368  |
| 7    568  46  | 468   3    1245 |  128   689   1689  |
| 356  3568 1   | 689   569  259  |  238   4     7     |
+---------------+-----------------+--------------------+
| 3456 356  369 | 2     4789 479  | 7+348  1     3458  |
| 45   7    29  | 3     1489 149  |  6     258   458   |
| 8    1    23  | 5     4+7  6    |  9     2+7   3+4   |
+---------------+-----------------+--------------------+

[Marty R.]

Interesting, but though i see the implications you call a loop here, in my opinion it does not allow you to eliminate the 7 in r7c7.

The problem is, that not every part of the loop alone implies the next one, e.g. r1c7=4 does not imply r13c8<>7 or r9c9=3 does not imply r7c7=8 (the loop is not built by a chain, but by a net).
So not only the loop digits or only their opposites can be valid for these cells.
For example your loop does not exclude those digits (left of the + sign).

Code: Select all

+---------------+-----------------+--------------------+
| 369  36   5   | 1     4679 8    | 4+7   69+7   2     |
| 169  2    7   | 469   4569 459  | 8+14   3     14689 |
| 169  4    8   | 679   2    3    | 1+7   7+569  1569  |
+---------------+-----------------+--------------------+
| 2    9    346 | 4678  1467 147  |  5     68    1368  |
| 7    568  46  | 468   3    1245 |  128   689   1689  |
| 356  3568 1   | 689   569  259  |  238   4     7     |
+---------------+-----------------+--------------------+
| 3456 356  369 | 2     4789 479  | 7+348  1     3458  |
| 45   7    29  | 3     1489 149  |  6     258   458   |
| 8    1    23  | 5     4+7  6    |  9     2+7   3+4   |
+---------------+-----------------+--------------------+

OK, thanks. I thought any chain qualified as a loop if it started and ended in the same house. It looks like you're saying that a loop needs to proceed in a continuous fashion.

[eleven]

Todays sudoku is too easy, so i tried to find a good real world example - but only found a bad one. However,
the nice thing about loops is, that if you have the implications in the one direction, they must be valid in the other too. And either all statements are right or all must be false (different).

So if we exclusively talk about a monkey and me, you might form this loop:
Its the monkey => it cannot solve sudokus => it's not a real man => its the monkey
Having this, you automatically know, that if its not a real man, it follows, that it cannot solve sudokus ...
[added the AIC]
(monkey=me)-(not solve=solve)-(no man=man)-monkey loop (the weak links become strong links)

But you did something like this:
Its the monkey => it likes bananas => it lives on the trees => its the monkey
But it that is a correct loop, you can follow, that i am a monkey too (ok, who knows).