The New Sudoku Players' Forum

[yzfwsf]

so its not coded into AIC yet? only als+aic

No, AF(regular fish) is already coded in the ALS AIC, but your example is not AF, but a finned fish.
At your PM:
ALS AIC Type 1: 8r36c5 = r3c8(r36\c589) - (8=1265)r2478c8 - r36c8 = r36c5(r36\c568) - (5=284)r9c357 - 8r9c7 = 8r4c47(c47\r249) => r4c5<>8
ALS AIC Type 1: 8r36c9 = r3c8(r36\c589) - (8=1265)r2478c8 - r36c8 = r36c5(r36\c568) - (5=284)r9c357 - 8r9c7 = 8r4c47(c47\r249) => r4c9<>8

[StrmCkr]

so its not coded into AIC yet? only als+aic

Code: Select all

+---------------------+-----------------------+---------------------+
| 8      5      179   | 49      6      2      | 79      3     149   |
| 1369   369    4     | 9-5(8)  7      39(5)  | 289(5)  1258  129   |
| 2      379    379   | 1       3589   349(5) | 6       578   489   |
+---------------------+-----------------------+---------------------+
| 13469  23469  5     | 29(48)  12389  7      | 289     268   23689 |
| 13679  8      12379 | 259     12359  139(5) | 7(5)    4     2369  |
| 3479   23479  239   | 6       23589  39(45) | 1       57    2389  |
+---------------------+-----------------------+---------------------+
| 3479   23479  6     | 279     129    8      | 24      12    5     |
| 579    279    2789  | 2579    4      19     | 3       1268  1268  |
| 45     1      28    | 3       25     6      | 248     9     7     |
+---------------------+-----------------------+---------------------+

AIC + almost Fish
(8)r2c4 = r4c4 - (4)r4c4 = r6c6 - (5)r6c6 = [ c67 / r235 ] {finned x-wing} => r2c4 <> 5

I suppose this is the original sudoku:

Code: Select all

+-------+-------+-------+
| 8 5 . | . . 2 | . 3 . |
| . . 4 | . 7 . | . . . |
| 2 . . | 1 . . | 6 . . |
+-------+-------+-------+
| . . 5 | . . 7 | . . . |
| . 8 . | . . . | . 4 . |
| . . . | 6 . . | 1 . . |
+-------+-------+-------+
| . . 6 | . . 8 | . . 5 |
| . . . | . 4 . | 3 . . |
| . 1 . | 3 . . | . 9 7 |
+-------+-------+-------+

What are the (not basic) steps before you found this elimination(R2C4<>5)?

2 hidden singles, blr, hidden pair, 2 x 2 string kites and an als-xz gets to the above pm state this move is valid from

Hidden Text: Show

Almost Locked Set XZ-Rule: A=r8c1234 {25789}, B=r9c35 {258}, X=8, Z=5 => r8c6<>5

same grid I originally purposed
AF + aic & or als style of moves on way back in 2011: just updated the presentation to be cleaner

[StrmCkr]

so its not coded into AIC yet? only als+aic

No, AF(regular fish) is already coded in the ALS AIC, but your example is not AF, but a finned fish.
At your PM:
ALS AIC Type 1: 8r36c5 = r3c8(r36\c589) - (8=1265)r2478c8 - r36c8 = r36c5(r36\c568) - (5=284)r9c357 - 8r9c7 = 8r4c47(c47\r249) => r4c5<>8
ALS AIC Type 1: 8r36c9 = r3c8(r36\c589) - (8=1265)r2478c8 - r36c8 = r36c5(r36\c568) - (5=284)r9c357 - 8r9c7 = 8r4c47(c47\r249) => r4c9<>8

i see it as an almost fish {as it has +1 cell} not covered by base/cover + k

alright so yours is only: R&C types of base/cover with +x cells outside the base/cover
- noted: still impressive

[StrmCkr]

so its not coded into AIC yet? only als+aic

Code: Select all

+---------------------+-----------------------+---------------------+
| 8      5      179   | 49      6      2      | 79      3     149   |
| 1369   369    4     | 9-5(8)  7      39(5)  | 289(5)  1258  129   |
| 2      379    379   | 1       3589   349(5) | 6       578   489   |
+---------------------+-----------------------+---------------------+
| 13469  23469  5     | 29(48)  12389  7      | 289     268   23689 |
| 13679  8      12379 | 259     12359  139(5) | 7(5)    4     2369  |
| 3479   23479  239   | 6       23589  39(45) | 1       57    2389  |
+---------------------+-----------------------+---------------------+
| 3479   23479  6     | 279     129    8      | 24      12    5     |
| 579    279    2789  | 2579    4      19     | 3       1268  1268  |
| 45     1      28    | 3       25     6      | 248     9     7     |
+---------------------+-----------------------+---------------------+

AIC + almost Fish
(8)r2c4 = r4c4 - (4)r4c4 = r6c6 - (5)r6c6 = [ c67 / r235 ] {finned x-wing} => r2c4 <> 5

Starting with the same resolution state, this elimination is obtained by a z-chain[4]:

Code: Select all

z-chain[4]: c4n8{r2 r4} - b5n4{r4c4 r6c6} - c6n5{r6 r5} - c7n5{r5 .} ==> r2c4≠5

are u sure its not the g-whip[2]: c6n5{r2 r456} - c7n5{r5 .} ==> r2c4 <> 5 you responded with in 2011 to the exact same grid state.

[denis_berthier]

Starting with the same resolution state, this elimination is obtained by a z-chain[4]:

Code: Select all

z-chain[4]: c4n8{r2 r4} - b5n4{r4c4 r6c6} - c6n5{r6 r5} - c7n5{r5 .} ==> r2c4≠5

are u sure its not the g-whip[2]: c6n5{r2 r456} - c7n5{r5 .} ==> r2c4 <> 5 you responded with in 2011 to the exact same grid state.

It can be both. The z-chain[4] is closer to the finned-fish.

[marek stefanik]

are u [Denis] sure its not the g-whip[2]: c6n5{r2 r456} - c7n5{r5 .} ==> r2c4 <> 5 you responded with in 2011 to the exact same grid state.

The g-whip[2] was never valid in the first place, it's not an antiking sudoku. The weak link 5r456c6 – 5r5c7 is not proven anywhere in Denis' posts.

Marek

[denis_berthier]

are u [Denis] sure its not the g-whip[2]: c6n5{r2 r456} - c7n5{r5 .} ==> r2c4 <> 5 you responded with in 2011 to the exact same grid state.

The g-whip[2] was never valid in the first place, it's not an antiking sudoku. The weak link 5r456c6 – 5r5c7 is not proven anywhere in Denis' posts.

A g-link never has to be proven in a particular resolution state. It is a structural property.
In the present case, without ever looking at the RS, this is not a g-link (r5c7 is not even in the same block as r456c6).

Without any reference to my supposed 2011 post, I can't say more. I may have made an error in some manual construction. What I am certain of is, SudoRules can't have made such an error.

[StrmCkr]

Code: Select all

(4)R4C4  =  (8)R2C4
||
(8) R4C4 =  (4)R6C6 
                 |
                (5) almost finned fish in cells
                  R2356C6   -  R25C7
 ==>> R24 <> 5

Hi StrmCkr,

Here is an interpretation of this elimination in terms of g-whips:

g-whip[2]: c6n5{r2 r456} - c7n5{r5 .} ==> r2c4 <> 5

[denis_berthier]

.
OK, I made an error at that time. This is not a g-whip (for the reasons stated in my previous post).

But no possible error in the z-chain[4]; it was found by SudoRules.