Code: Select all
.----------------.-------------------.-----------------.
| 29 1 8 | 7 *35 6 | 259 #359 4 |
| 79 3 4 | 158 58 2 | 1579 5789 6 |
| 27 6 5 | 138 4 9 | 127 -378 *23 |
:----------------+-------------------+-----------------:
| 4 28 123 | 238 9 378 | 6 137 5 |
|*135 9 7 | 2-356 2-356 -34 | 8 1-34 #23 |
| 6 258 23 | 2358 1 3478| 27 347 9 |
:----------------+-------------------+-----------------:
| 15 4 1269 | 268 2678 18 | 3 59 78 |
|#135 25 12-39| 4 2-378 138 | 59 6 78 |
| 8 7 *36 | 9 #36 5 | 4 2 1 |
'----------------'-------------------'-----------------'
- (3): r1c5 = r1c8 - r3c9 = r5c9 - r5c1 = r8c1 - r9c3 = r9c5 - r1c5.
Many of the eliminations for digit "3" which are found one by one by the Sudocue solver are taken care of in one blow by the X-cycle.
Following up these eliminations, and making use of a naked triple of "259" in r8c237, we come to this position:
Code: Select all
.---------------.------------------.--------------.
| 29 1 8 | 7 35 6 | 259 359 4 |
| 79 3 4 | 158 58 2 | 1579 5789 6 |
| 27 6 5 | 138 4 9 | 127 78 23 |
:---------------+------------------+--------------:
| 4 28 1 | 238 9 378 | 6 37 5 |
| 3-5 9 7 |*26+5 *26+5 4 | 8 1 23 |
| 6 258 23 | 2358 1 378 | 27 4 9 |
:---------------+------------------+--------------:
|#15 4 269 |*26+8 *26+78 #18 | 3 59 #78 |
| 13 25 29 | 4 78 138 | 59 6 78 |
| 8 7 36 | 9 36 5 | 4 2 1 |
'---------------'------------------'--------------'
(5=26)r5c45 - UR - (26=(7or8))r7c45 - (178=5)r7c169 => r5c1 <> 5.
The rest is easy after this elimination.