The New Sudoku Players' Forum

[ArkieTech]

Code: Select all

 *-----------*
 |..4|..8|6..|
 |...|...|285|
 |..6|.5.|.1.|
 |---+---+---|
 |2.5|.74|..6|
 |.4.|...|.2.|
 |6..|19.|8.4|
 |---+---+---|
 |.9.|.3.|5..|
 |153|...|...|
 |..8|9..|3..|
 *-----------*


Play/Print this puzzle online

[Leren]

Code: Select all

*------------------------------------------------------------------------*
|  5      127    4       | 237    12     8       | 6      37     9       |
|gb39     17    a1-9a    | 3467   46    c13679   | 2      8      5       |
| g389b   278    6       | 237    5      379c    | 4      1      37      |
|------------------------+-----------------------+-----------------------|
|  2      18     5       | 38     7      4       | 19     39     6       |
| f89     4      19      | 5     e68    d36      | 17     2      37      |
|  6      3      7       | 1      9      2       | 8      5      4       |
|------------------------+-----------------------+-----------------------|
|  47     9      2       | 4678   3      167     | 5      467    18      |
|  1      5      3       | 24678  468    67      | 79     4679   28      |
|  47     6      8       | 9      12     5       | 3      47     12      |
*------------------------------------------------------------------------*

9 r2c3 - 9 r3c1 = 9 r3c6 - 3 r3c6;

9 r2c3 - (9=3) r2c1      - 3 r2c6 = (3-6) r5c6 = (6-8) r5c5 = (8-9) r5c1 = r23c1 - 9 r2c3; => - 9 2rc3; stte

Leren

[SteveG48]

Code: Select all

 *---------------------------------------------------------------------*
 | 5      127    4      |  237    12     8      | 6      37     9      |
 | 39     17     19     |  3467   46     13679  | 2      8      5      |
 | 389   d278    6      | d237    5      379    | 4      1     d37     |
 *----------------------+-----------------------+----------------------|
 | 2      1-8    5      |ac38     7      4      | 19     39     6      |
 | 89     4      19     |  5      68    b36     | 17     2     c37     |
 | 6      3      7      |  1      9      2      | 8      5      4      |
 *----------------------+-----------------------+----------------------|
 | 47     9      2      |  4678   3      167    | 5      467    18     |
 | 1      5      3      |  24678  468    67     | 79     4679   28     |
 | 47     6      8      |  9      12     5      | 3      47     12     |
 *---------------------------------------------------------------------*


(8=3)r4c4 - 3r5c6 = r4c4&r5c9 - (3=278)r3c249 => -8 r4c2 ; stte

[pjb]

Code: Select all

  5       127     4      | 237    12     8      | 6      37     9     
 b39      17      19     | 3467   46    a13679  | 2      8      5     
Bc389d    278     6      | 237    5     A379    | 4      1      37     
-------------------------+----------------------+---------------------
  2       18      5      | 38     7      4      | 19     39     6     
  89c     4       19     | 5      68b    36a    | 17     2      37     
  6       3       7      | 1      9      2      | 8      5      4     
-------------------------+----------------------+---------------------
  47      9       2      | 4678   3      167    | 5      467    18     
  1       5       3      | 24678  468    67     | 79     4679   28     
  47      6       8      | 9      12     5      | 3      47     12     


(3)r2c6 - r2c1 = (3-8)r3c1
(9)r3c6 = (9-8)r3c1
(6)r5c6 = (6-8)r5c5 = r5c1 - (8)r3c1 => -8 r3c1; stte

or single chain

(3=7)r3c9* - (7=3)r1c8 - (3=9)r4c8 - (9=1)r4c7 - (1=8)r4c2 - (78=2)r3c2* - (27=3)r3c4* => -3 r3c16; stte

Phil

[JC Van Hay]

Code: Select all

+----------------+----------------------+--------------+
| 5      127  4  | 237    12    8       | 6   37    9  |
| (39)   17   19 | 3467   46    1679(3) | 2   8     5  |
| 38(9)  278  6  | 237    5     7(39)   | 4   1     37 |
+----------------+----------------------+--------------+
| 2      18   5  | 38     7     4       | 19  39    6  |
| (89)   4    19 | 5      (68)  -6(3)   | 17  2     37 |
| 6      3    7  | 1      9     2       | 8   5     4  |
+----------------+----------------------+--------------+
| 47     9    2  | 4678   3     167     | 5   467   18 |
| 1      5    3  | 24678  468   67      | 79  4679  28 |
| 47     6    8  | 9      12    5       | 3   47    12 |
+----------------+----------------------+--------------+

3r5c6=*M-Ring[(9=3)r2c1-3r2c6=*(3-9)r3c6=9r3c1]-(9=86)r5c15 -> [3r5c6==6r5c5]-6r5c6; stte

[eleven]

Just 2 variations of the solutions by Leren and Steve:
3r1c4=r1c8-(3=8)r4c278-(8=3*)r4c249-r3c1=r2c1 => -3r3c6*,r2c46
(1=83)r4c24-(8|3=27)r3c24-(7=3)r3c9-(3=1)r5c79 => -1r5c3

[Cenoman]

Code: Select all

 +------------------+-----------------------+------------------+
 | 5     127   4    | 237     12    8       | 6    37     9    |
 | 39    17    19   | 3467    46    13679   | 2    8      5    |
 |d89-3  278   6    | 237     5    d79-3    | 4    1     a37   |
 +------------------+-----------------------+------------------+
 | 2     18    5    | 38      7     4       | 19   39     6    |
 |c89    4     19   | 5      b68   b36      | 17   2     b37   |
 | 6     3     7    | 1       9     2       | 8    5      4    |
 +------------------+-----------------------+------------------+
 | 47    9     2    | 4678    3     167     | 5    467    18   |
 | 1     5     3    | 24678   468   67      | 79   4679   28   |
 | 47    6     8    | 9       12    5       | 3    47     12   |
 +------------------+-----------------------+------------------+

(3=7)r3c9 - (7=8)r5c569 - r5c1 = (HP89)r3c16 => -3 r3c16; stte

Cenoman
Edited cell references

[bat999]

Code: Select all

.----------------.---------------------.--------------.
|  5    127   4  | 237     12    8     | 6   37    9  |
| b39   17   b19 | 3467    46   c13679 | 2   8     5  |
|  389  278   6  | 237     5     379   | 4   1     37 |
:----------------+---------------------+--------------:
|  2    18    5  | 38      7     4     | 19  39    6  |
| a89   4    a19 | 5      a68    3-6   | 17  2     37 |
|  6    3     7  | 1       9     2     | 8   5     4  |
:----------------+---------------------+--------------:
|  47   9     2  | 4678    3    c167   | 5   467   18 |
|  1    5     3  | 24678   468  c67    | 79  4679  28 |
|  47   6     8  | 9       12    5     | 3   47    12 |
'----------------'---------------------'--------------'

(6=1)r5c135 - (1=39)r2c13 - (3|9=6)r278c6 => -6 r5c6; stte

[eleven]

(3=7)r3c9 - (7=8)e569 - e1 = (HP89)r3c16 => -3 r3c16; stte

So simple.

If HP stands for hidden pair, it is confusing for me, that it is used here. The missing of the 8 in r5c1 does not lead to a hidden pair 89 in row 3, but to 2 singles 8 and 9.
So i would prefer just to leave that out (-8r5c1 = 89r3c16).

If e.g. you would continue -8r5c1 = r4c2 - r2c3 = hp89r3c16, i would be happy with the notation (only 2 cells for 89 left in r3).

[Edit: typo]

[SteveG48]

(3=7)r3c9 - (7=8)e569 - e1 = (HP89)r3c16 => -3 r3c16; stte

I follow the solution, but I'm not familiar with the e notation. What's that?

[Cenoman]

eleven wrote:
If HP stands for hidden pair, it is confusing for me, that it is used here. The missing of the 8 in r5c1 does not lead to a hidden pair 89 in row 3, but to 2 singles 8 and 9.
So i would prefer just to leave that out (-8r5c1 = 89r3c16).

If e.g. you would continue -8r5c1 = r4c2 - r2c2 = hp89r3c16, i would be happy with the notation (only 2 cells for 89 left in r3).

I remember being confused in years 2007-2010 when sudoku experts started to write ALS's (x=y)cells n1.n2.n3... because x or y digits are not necessarily candidates in all cells n1.n2.n3... Then the weak links that precede or follow the ALS need a visual checking on the grid.

Here the technique used is AHS (cells r3c16 where 9 is locked) and more accurately, the inference is the weak link (8-3)r3c16. You caught it, of course. I'am not trying to teach that to eleven, nor to anyone else !
For AHS's of 3 or more cells, it is not easy for readers to check such links when they have to spot the locking digits by themselves. My practise is to indicate the locking digits to readers.
The label "HP", "HT", ... is just an indication of the pattern) Might be "AHS" as well, or nothing at all, as in your proposal (-8r5c1 = 89r3c16). BTW whether 89r3c16 is a true pair or a set of two singles changes nothing to the inferences of the pattern (all other digits are ejected from the two cells...) and my label changes nothing either.

I am not much fond of your alternate proposal -8r5c1 = r4c2 - r3c2 = hp89r3c16 (supposed a typo...), because if I use the links to 8r3c2, i.e. to the complementary 8's in row 3 (might be a group), then I'd better finish the chain with the ALS:
(3=7)r3c9 - (7=8)r5c569 - r5c1 = r4c2 - (8=3)r3c248 (but such chain has 4 strong links vs 3)

I generally keep the AHS when it has less cells than the complementary ALS. I am ready to follow any notation preference (as already told several times). The "no label" proposal suits me.

SteveG48 wrote: I follow the solution, but I'm not familiar with the e notation. What's that?

Hi Steve, just a lack of care. Corrected now. Thank you.
I was present on a French forum using "Excel A1" notation, I am present on Andrew Stuart's forum using letters for rows and numbers for columns, on an Australian forum using "Chess notation" (letters for columns, lines numbered from down to top) and now on this forum using rc notation (and my solver has not yet learnt rc notation).

Cenoman

[eleven]

I don't know, if others care.
But when i read HP (e.g. JC is one using it sometimes), i am looking for a hidden pair, and here i can't find one.
So any other label (including none) would be ok for me.

Thanks for pointing out the typo.