There is a large fish on digit 7 eliminating 7 from r1c8.
For me it is easier to justify the elimination as follows
- Code: Select all
.---------------------------------------------------------------------.
| 18 3 12 | 16789 59 Ea1678 | 4 12-7 58 |
| 1458 1458 7 | 148 2 18 | 6 3 9 |
| 6 1248 9 | 148-7 45 3 |h127 127 58 |
|-----------------------+----------------------+----------------------|
| 3 e47 12 | 12 6 9 | 5 8 f47 |
| 178 1278 5 | 3 78 4 | 9 6 12 |
| 1478 9 6 | 5 78 12 |g127 1247 3 |
|-----------------------+----------------------+----------------------|
|Cc157 Cc157 3 | 2479 49 Db27 | 8 1479 6 |
| 2 6 8 | 479 1 5 | 3 479 47 |
| 9 Bd17 4 | 68 3 68 |A12(7) 5 12 |
'---------------------------------------------------------------------'
Since
(7)r1c6 == (7)r9c2 since (7): r1c6 = r7c6 - r7c12 = r9c2
(7)r6c7 -- (7)r9c2 since (7): r9c2 - r4c2 = r4c9 - r6c7
We have
=> [(7)r1c6 == r9c2 -- r6c7 =* r3c7] = (7*)r9c7 - (7)r9c2 == (7)r1c6 => -7 r1c8; ste
Another way based on extended one-digit coloring
- Code: Select all
.--------------------------------------------------------------------.
| 18 3 12 | 16789 59 167Y8* | 4 12-7 58 |
| 1458 1458 7 | 148 2 18 | 6 3 9 |
| 6 1248 9 | 1478 45 3 | 127o 127 58 |
|----------------------+----------------------+----^-----------------|
| 3 47 . 12 --> | 12 6 9 | 5 '-- 8----- 47o |
| 178 1278 | 5 | 3 78 4 | 9 6 12 |
| 1478 9 | 6 | 5 78 12 | 127 1247 3 |
|------------/---------+----------------------+----------------------|
| 157 157/.- 3 --<- | 2479 --49 --- 27O* | 8 1479 6 |
| 2 6 / | 8 | 479 1 5 | 3 479 47 |
| 9 17o<' 4 | 68 3 68 | 127 5 12 |
'--------------------------------------------------------------------'
Extended Coloring on digit 7 with colors Y(yellow) and O(orange)
=> -7 r1c8; ste