The New Sudoku Players' Forum

[ArkieTech]

Code: Select all

 *-----------*
 |3..|417|...|
 |.1.|...|...|
 |..4|83.|5..|
 |---+---+---|
 |4.6|...|..9|
 |9.1|.5.|6.3|
 |2..|...|8.1|
 |---+---+---|
 |..3|.46|1..|
 |...|...|.9.|
 |...|725|..6|
 *-----------*


Play/Print this puzzle online

[Cenoman]

Code: Select all

 +-------------------+------------------+---------------------+
 |  3    25    258   |  4    1    7     |  9     6     28     |
 |  7-8  1    d289   |  5    6   d29    |  347  d238   2478   |
 |  67   69    4     |  8    3    29    |  5     1     27     |
 +-------------------+------------------+---------------------+
 |  4    38    6     |  13   7    138   |  2     5     9      |
 |  9    78    1     |  2    5    48    |  6     47    3      |
 |  2    357   57    |  6    9    34    |  8     47    1      |
 +-------------------+------------------+---------------------+
 | a58   27    3     |  9    4    6     |  1     28    2578   |
 |  56   46    27    |  13   8    13    |  47    9     2457   |
 |  1    49   b89    |  7    2    5     |  34   c38    6      |
 +-------------------+------------------+---------------------+

(8)r7c1 = r9c3 - (8=3)r9c8 - (3=298)r2c268 => -8 r2c1; ste

[SteveG48]

Code: Select all

 *-----------------------------------------------------------*
 | 3     25    258   | 4     1     7     | 9     6    a28    |
 |c78    1     289   | 5     6     29    | 34-7  238   248-7 |
 | 6-7  a69    4     | 8     3    a29    | 5     1    a27    |
 *-------------------+-------------------+-------------------|
 | 4     38    6     | 13    7     138   | 2     5     9     |
 | 9     78    1     | 2     5     48    | 6     47    3     |
 | 2     357   57    | 6     9     34    | 8     47    1     |
 *-------------------+-------------------+-------------------|
 |c58    27    3     | 9     4     6     | 1     28   b2578  |
 | 56   b46    27    | 13    8     13    |b47    9     2457  |
 | 1     49    89    | 7     2     5     | 34    38    6     |
 *-----------------------------------------------------------*


(7=9628)r1c9,r3c269 - (6|2|8=475)r7c9,r8c27 - (5=87)r27c1 => -7 r2c79,r3c1 ; stte

[Ngisa]

Code: Select all

+--------------------+------------------+----------------------+
| 3      25      258 | 4      1     7   | 9       6       28   |
|b78*    1       289 | 5      6     29  | 347    d238     2478 |
|a67    a269     4   | 8      3    a29  | 5       1      a7-2  |
+--------------------+------------------+----------------------+
| 4      38      6   | 13     7     138 | 2       5       9    |
| 9      78      1   | 2      5     48  | 6       47      3    |
| 2      357     57  | 6      9     34  | 8       47      1    |
+--------------------+------------------+----------------------+
| 58     27      3   | 9      4     6   | 1       278     2578 |
| 56    b46      27  | 13     8     13  | 347     9       2457 |
| 1     c49     c89  | 7      2     5   | 34     c3*8     6    |
+--------------------+------------------+----------------------+


A Net
(2967)r3c1269 - (7=8*)r2c1&(6=4)r8c2 - (4=983*)r9c238 - (3*8*=2)r2c8 => - 2r3c9; stte

Clement

[SteveG48]

Code: Select all

+--------------------+------------------+----------------------+
| 3      25      258 | 4      1     7   | 9       6       28   |
|b78*    1       289 | 5      6     29  | 347    d238     2478 |
|a67    a269     4   | 8      3    a29  | 5       1      a7-2  |
+--------------------+------------------+----------------------+
| 4      38      6   | 13     7     138 | 2       5       9    |
| 9      78      1   | 2      5     48  | 6       47      3    |
| 2      357     57  | 6      9     34  | 8       47      1    |
+--------------------+------------------+----------------------+
| 58     27      3   | 9      4     6   | 1       278     2578 |
| 56    b46      27  | 13     8     13  | 347     9       2457 |
| 1     c49     c89  | 7      2     5   | 34     c3*8     6    |
+--------------------+------------------+----------------------+


A Net
(2967)r3c1269 - (7=8*)r2c1&(6=4)r8c2 - (4=983*)r9c238 - (3*8*=2)r2c8 => - 2r3c9; stte

Clement

Hi, Clement. I like what you're doing, but not the way you've written it. Your first term has to be true, since 2967 are the only candidates in those four cells, so it doesn't do what you want.

Write (67)r3c19 = 7r3c1&6r3c2 - . . . and the rest of your chain works.

[Ngisa]

Code: Select all

+--------------------+------------------+----------------------+
| 3      25      258 | 4      1     7   | 9       6       28   |
|b78*    1       289 | 5      6     29  | 347    d238     2478 |
|a67    a269     4   | 8      3    a29  | 5       1      a7-2  |
+--------------------+------------------+----------------------+
| 4      38      6   | 13     7     138 | 2       5       9    |
| 9      78      1   | 2      5     48  | 6       47      3    |
| 2      357     57  | 6      9     34  | 8       47      1    |
+--------------------+------------------+----------------------+
| 58     27      3   | 9      4     6   | 1       278     2578 |
| 56    b46      27  | 13     8     13  | 347     9       2457 |
| 1     c49     c89  | 7      2     5   | 34     c3*8     6    |
+--------------------+------------------+----------------------+


A Net
(2967)r3c1269 - (7=8*)r2c1&(6=4)r8c2 - (4=983*)r9c238 - (3*8*=2)r2c8 => - 2r3c9; stte

Clement

Hi, Clement. I like what you're doing, but not the way you've written it. Your first term has to be true, since 2967 are the only candidates in those four cells, so it doesn't do what you want.

Write (67)r3c19 = 7r3c1&6r3c2 - . . . and the rest of your chain works.

Yes, my first assumption is that (2)r3c9 is true, then you have (9)r3c6, (6)r3c2, (7)r3c1. Anything wrong with that?

[SpAce]

(2967)r3c1269 - (7=8*)r2c1&(6=4)r8c2 - (4=983*)r9c238 - (3*8*=2)r2c8 => - 2r3c9; stte

Write (67)r3c19 = 7r3c1&6r3c2 - . . . and the rest of your chain works.

That's a very kind assessment of you, Steve. The intended logic works, yes, but the way it's written does not. I see issues in every single term of that chain.

my first assumption is that (2)r3c9 is true, then you have (9)r3c6, (6)r3c2, (7)r3c1. Anything wrong with that?

Not really, but that's not what's written in your chain. Steve already explained why, and I know I've done the same before. Doesn't seem to make a dent. I don't know why you insist on starting with a weak link anyway.

Here's how I'd write it with a memory chain:

(7)r3c9 = (78*6-9)b1p748 = (983)r9c238 - (3|*8=2)r2c8 => -2 r3c9; stte

The same without memory:

(7)r3c9 = (76)r3c12 - (7)r2c1|(9)r3c2 = (8)r2c1&(983)r9c238 - (8|3=2)r2c8 => -2 r3c9; stte

[Ngisa]

(2967)r3c1269 - (7=8*)r2c1&(6=4)r8c2 - (4=983*)r9c238 - (3*8*=2)r2c8 => - 2r3c9; stte

Write (67)r3c19 = 7r3c1&6r3c2 - . . . and the rest of your chain works.

That's a very kind assessment of you, Steve. The intended logic works, yes, but the way it's written does not. I see issues in every single term of that chain.

my first assumption is that (2)r3c9 is true, then you have (9)r3c6, (6)r3c2, (7)r3c1. Anything wrong with that?

Not really, but that's not what's written in your chain. Steve already explained why, and I know I've done the same before. Doesn't seem to make a dent. I don't know why you insist on starting with a weak link anyway.

Here's how I'd write it with a memory chain:

(7)r3c9 = (78*6-9)b1p748 = (983)r9c238 - (3|*8=2)r2c8 => -2 r3c9; stte

The same without memory:

(7)r3c9 = (76)r3c12 - (7)r2c1|(9)r3c2 = (8)r2c1&(983)r9c238 - (8|3=2)r2c8 => -2 r3c9; stte

I said 2 is in r3c9, is that a weak link?

[SpAce]

I don't know why you insist on starting with a weak link anyway.

I said 2 is in r3c9, is that a weak link?

Obviously not (it's a node and not a link), but it's related. Since you assume your starting node to be true it forces the first link to be weak just like you wrote it ('-' is a weak link and '=" is a strong link, in case you didn't know the terms). That's not how AICs are usually written, and there's almost never a good reason to do that. Normally you don't write them that way either, which is why I don't understand why you sometimes do.

It's a minor problem here anyway. A bigger problem is that the link doesn't even work because your starting node is written incorrectly, just like Steve said. If you really, really want to start with that node and a weak link, you should write (2,9,6,7)r3c9621. That fixes the digits into specific cells like you intended. I'd rather write (2,7,6)r3c912, though.

Here's a couple of corrected versions of what you intended:

(2,9,6,7)r3c9621 - (7)r2c1|(6)r8c2 = (8*)r2c1&(4)r8c2 - (4=983)r9c238 - (3|*8=2)r2c8 => -2 r3c9; stte

(2,9,6,7)r3c9621 - (7|6=8*4)r2c1,r8c2 - (4=983)r9c238 - (3|*8=2)r2c8 => -2 r3c9; stte

Because of the starting weak link, they're basically contradiction chains instead of normal AICs.

PS. This is incorrect: (7=8*)r2c1&(6=4)r8c2.