- Code: Select all
+------------------------+----------------------+---------------------+
| 3 (1678) (1267) | 478 5 47(12) | 9 468 48(1) |
| (1678) 9 5 | 3478 13478 147 | 1368 3468 2 |
| (128) 4 12 | 6 12389 129 | 1358 358 7 |
+------------------------+----------------------+---------------------+
| 5678 35678 9 | 2 347 4567 | 358 1 348 |
| 4 13568 1236 | 359 139 1569 | 7 23589 389 |
| 57(12) 1357 1237 | 34579 13479 8 | 235 23459 6 |
+------------------------+----------------------+---------------------+
| 9 137 1347 | 478 6 247 | 1238 2378 5 |
| 567 3567 3467 | 1 24789 24579 | 2368 236789 389 |
| 567(1) 2 8 | 579 79 3 | 4 679 9-1 |
+------------------------+----------------------+---------------------+
One of {r1c23,r23c1} contains 2 (out of 3) of the digits {6,7,8}.
If it's r1c23, then 2r1c6 and 1r1c9 are forced.
If it's r23c1, then 2c1c6 and 1r9c1 are forced.
Either way, 1r9c9 must be false ... stte.
Alternatively: (1=(4|8))r1c9 - 4678r1c2348 = (1&2)(r1c23,r3c3) - ((1|2)=5678)r2348c1 - ((5|6|7)=1)r9c1 => -1r9c9, stte.