The New Sudoku Players' Forum

[ArkieTech]

Code: Select all

 *-----------*
 |72.|64.|.59|
 |5..|.89|..2|
 |...|2.5|...|
 |---+---+---|
 |.65|...|9.3|
 |97.|...|.61|
 |2.1|...|57.|
 |---+---+---|
 |...|9.8|...|
 |6..|52.|..4|
 |35.|.64|.97|
 *-----------*


Play/Print this puzzle online

[Leren]

Code: Select all

*--------------------------------------------------------------------------------*
| 7       2      b38       | 6       4       13       | 138     5       9        |
| 5       134     6        | 37      8       9        | 1347    134     2        |
| 148     89      3489     | 2       137     5        | 13478   1348    6        |
|--------------------------+--------------------------+--------------------------|
| 48      6       5        | 478     17      127      | 9       24      3        |
| 9       7      c348      | 348     5       23       |d24      6       1        |
| 2       34      1        | 34      9       6        | 5       7       8        |
|--------------------------+--------------------------+--------------------------|
| 14      14      27       | 9       37      8        | 6       23      5        |
| 6       89      789      | 5       2       37       | 138     138     4        |
| 3       5      a28       | 1       6       4        |e8-2     9       7        |
*--------------------------------------------------------------------------------*

(2=8) r9c3 - (8=3) r1c3 - (38=4) r5c3 - (4=2) r5c7 - r9c7 => r9c7 <> 2; stte

Leren

[storm_norm22]

x-wing on 8
x-wing on 3

Code: Select all

+----------------+---------------+---------------+
| 7   2    -3(8) | 6   4    13   | 13(8)  5    9 |
| 5   134  6     | 37  8    9    | 147    14   2 |
| 14  89   349   | 2   137  5    | 1347   138  6 |
+----------------+---------------+---------------+
| 8   6    5     | 47  17   127  | 9      24   3 |
| 9   7    4(3)  | 8   5    (23) | 4(2)   6    1 |
| 2   34   1     | 34  9    6    | 5      7    8 |
+----------------+---------------+---------------+
| 14  14   27    | 9   37   8    | 6      23   5 |
| 6   89   79    | 5   2    37   | 13     138  4 |
| 3   5    28    | 1   6    4    | (28)   9    7 |
+----------------+---------------+---------------+

(3)r5c3 = (3-2)r5c6 = (2)r5c7 - (2=8)r9c7 - (8)r1c7 = (8)r1c3; r1c3 <> 3

[Leren]

Assuming the x-wing on 8 and x-wing on 3:

(8=3) r1c3 - (3=4) r5c3 - (4=2) r5c7 - (2=8) r9c7 => r1c7, r9c3 <> 8; stte

My first move does not require the x-wings.

Leren

[ArkieTech]

Code: Select all

 *--------------------------------------------------------------------*
 | 7      2     c38     | 6      4      13     | 138    5      9      |
 | 5      134    6      | 37     8      9      | 1347   134    2      |
 | 148    89     3489   | 2      137    5      | 13478  1348   6      |
 |----------------------+----------------------+----------------------|
 | 48     6      5      | 478    17     127    | 9      24     3      |
 | 9      7     c348    | 348    5      23     |b24     6      1      |
 | 2      34     1      | 34     9      6      | 5      7      8      |
 |----------------------+----------------------+----------------------|
 | 14     14     27     | 9      37     8      | 6      23     5      |
 | 6      89     789    | 5      2      37     | 138    138    4      |
 | 3      5      2-8    | 1      6      4      |a28     9      7      |
 *--------------------------------------------------------------------*
als xy-wing
(8=2)r9c7-(2=4)r5c7-(4=38)r15c3 => -8r9c3; stte

[tlanglet]

For me, this seemed more difficult that a normal Vanhagen Fiendish.............

2r7c8=(2-7)r7c3=(7-9)r8c3=(9-4)r3c3=r5c3-(4=2)r5c7 => r4c8<>2

Ted

[tlanglet]

Code: Select all

*--------------------------------------------------------------------------------*
| 7       2      b38       | 6       4       13       | 138     5       9        |
| 5       134     6        | 37      8       9        | 1347    134     2        |
| 148     89      3489     | 2       137     5        | 13478   1348    6        |
|--------------------------+--------------------------+--------------------------|
| 48      6       5        | 478     17      127      | 9       24      3        |
| 9       7      c348      | 348     5       23       |d24      6       1        |
| 2       34      1        | 34      9       6        | 5       7       8        |
|--------------------------+--------------------------+--------------------------|
| 14      14      27       | 9       37      8        | 6       23      5        |
| 6       89      789      | 5       2       37       | 138     138     4        |
| 3       5      a28       | 1       6       4        |e8-2     9       7        |
*--------------------------------------------------------------------------------*

(2=8) r9c3 - (8=3) r1c3 - (38=4) r5c3 - (4=2) r5c7 - r9c7 => r9c7 <> 2; stte

Leren

Veeeeery nice
Ted

[Marty R.]

Code: Select all

*--------------------------------------------------------------------------------*
| 7       2      b38       | 6       4       13       | 138     5       9        |
| 5       134     6        | 37      8       9        | 1347    134     2        |
| 148     89      3489     | 2       137     5        | 13478   1348    6        |
|--------------------------+--------------------------+--------------------------|
| 48      6       5        | 478     17      127      | 9       24      3        |
| 9       7      c348      | 348     5       23       |d24      6       1        |
| 2       34      1        | 34      9       6        | 5       7       8        |
|--------------------------+--------------------------+--------------------------|
| 14      14      27       | 9       37      8        | 6       23      5        |
| 6       89      789      | 5       2       37       | 138     138     4        |
| 3       5      a28       | 1       6       4        |e8-2     9       7        |
*--------------------------------------------------------------------------------*

(2=8) r9c3 - (8=3) r1c3 - (38=4) r5c3 - (4=2) r5c7 - r9c7 => r9c7 <> 2; stte

Leren

Same but I used a different notation and don't know if it's valid.

(2=8)r9c3-(38=4)r15c3-(4-2)r5c7=>r9c7<>2

[eleven]

Same but I used a different notation and don't know if it's valid.

(2=8)r9c3-(38=4)r15c3-(4-2)r5c7=>r9c7<>2

At least i understand it as well as Leren's (just would make it 4=2 instead of 4-1).

I never understood, why so much is discussed about the notation, all have to admit, that for special cases there is no standardized notation anyway.
Personally i would prefer here to note the almost pair 38, the rest falls into place.

[Marty R.]

I never understood, why so much is discussed about the notation,

At least one person here (yours truly) just started using notation recently and the learning process has a ways to go.

[daj95376]

Interesting. Even my solver chose to ignore the ANS in r159c3.

Code: Select all

 +-----------------------------------------------------------------------+
 |  7      2     a38     |  6      4      13     |  138    5      9      |
 |  5      134    6      |  37     8      9      |  1347   134    2      |
 |  148    89     3489   |  2      137    5      |  13478  1348   6      |
 |-----------------------+-----------------------+-----------------------|
 |  48     6      5      |  478    17     127    |  9      24     3      |
 |  9      7     a348    |  348    5      23     | b24     6      1      |
 |  2      34     1      |  34     9      6      |  5      7      8      |
 |-----------------------+-----------------------+-----------------------|
 |  14     14     27     |  9      37     8      |  6      23     5      |
 |  6      89     789    |  5      2      37     |  138    138    4      |
 |  3      5     a28     |  1      6      4      |  8-2    9      7      |
 +-----------------------------------------------------------------------+
 # 57 eliminations remain

 (2=ANS=4)r915c3 - (4=2)r5c7  =>  r9c7<>2


[DonM]

Same but I used a different notation and don't know if it's valid.

(2=8)r9c3-(38=4)r15c3-(4-2)r5c7=>r9c7<>2

At least i understand it as well as Leren's (just would make it 4=2 instead of 4-1).

I never understood, why so much is discussed about the notation, all have to admit, that for special cases there is no standardized notation anyway.

Well, I don't admit it . As David Bird pointed out in an earlier post, the Eureka notation became reasonably standardized after a lot of discussion in the period of around 2006-2008. While it is true that some special cases such as Almost-AICs, Sue-de-Coq and the like may not be all that standardized, more basic cases such as any form of ALS/ANS have been standardized enough that, in the past, variations have been relatively slight.

But, a more important reason for discussing notation is when the notation does not accurately indicate the logic flow in a chain. Case in point is the ALS in the chain above being notated as (38=4)r15c3. The logic flow is that: if not 2 then 8 in r9c3 which leads to a locked set of digits 34 in r15c3, hence the ALS should be notated (8=34)r15c3 (ie. if not 8 then 34) just as ArchieTech accurately shows in his chain.

There was a lot of manual solving of puzzles far more difficult than most in this sub-forum on the Eureka forum (where the Eureka notation started) in 2007-2010 and most of us were able to easily understand each other's chains because there was reasonable standardization, but here I see too many instances of inaccurate notation or too many instances of solvers using their own shorthand which means that those such as Marty who are trying (to his credit) to learn notation are going to find it more difficult. Not to mention that I suspect that where a solver's notation is obscure, other solvers are less likely to appreciate the solution. Just sayin'.

[eleven]

If there is such a standardization, then please give me a link, where it is defined. I can't find one.
If it is so important for some people, one of them should have bothered to write one.

By the way i saw that you do like XSudo's "picture notation", which for me does not say more than: there is an elimination, try to find the logic behind.

[Added]
Home exercise: write this elimination in Eureka notation

if you need help, it is explained here.

[DonM]

If there is such a standardization, then please give me a link, where it is defined. I can't find one.
If it is so important for some people, one of them should have bothered to write one.

IMO, it's not very helpful to not only not address my points above, but also to demand a link when you've been around to know that hacking has totally wiped out the Eureka forum where all the Eureka-related threads originated.

By the way i saw that you do like XSudo's "picture notation", which for me does not say more than: there is an elimination, try to find the logic behind...

I'm not sure what my saying that Norm's XSudo image was a pretty picture has anything to do with translating a XSudo image of a complex chain into Eureka notation. So you don't like XSudo images- no one says you have to.

[JasonLion]

If you are asking someone to use standardized notation, which I agree is a good idea, it is important that there be some agreement about what the standard actually is and some way to access/refer to the contents of that agreement. If the Eureka forum posts explaining the standard no longer exist, it is important that some appropriate definition of how notation should be written exist somewhere else, otherwise it is no longer possible to use that format as a standard. Without a reference, new users have no way to learn how to use it and experienced users have no way to double check if they actually remember one of the more obscure aspects of the standard correctly.

I have seen some basic overviews of Eureka notation, for example http://www.sudocue.net/eureka-notation.php or http://www.dailysudoku.com/sudoku/forums/viewtopic.php?t=6708, but I suspect those descriptions aren't really complete enough to serve as a standard.