Code: Select all
+----------------------+----------------------+----------------------+
| 5 29 289 | 4 6 1789 | 3 12 127 |
| 7 4 2369 | 2359 19 159 | 1256 8 12 |
| 238 1 2368 | 23578 8 578 | 9 2456 247 |
+----------------------+----------------------+----------------------+
| 6 579 1589 | 89 3 2 | 1478 149 1479 |
| 123489 2379 12389 | 689 5 4689 | 124678 12469 123479 |
| 23489 239 2389 | 1 7 4689 | 2468 2469 5 |
+----------------------+----------------------+----------------------+
| 1239 23569 4 | 5689 189 15689 | 125 7 129 |
| 129 8 1259 | 579 149 14579 | 1245 3 6 |
| 19 569 7 | 569 2 3 | 145 1459 8 |
+----------------------+----------------------+----------------------+
Code: Select all
+----------------+----------------+----------------+
| 5 29 8 | 4 6 19 | 3 12 7 |
| 7 4 239 | 23 19 5 | 6 8 12 |
| 23 1 6 | 23 8 7 | 9 5 4 |
+----------------+----------------+----------------+
| 6 579 159 | 89 3 2 | 1478 149 19 |
| 48 279 129 | 689 5 468 | 1278 1269 3 |
| 48 239 239 | 1 7 468 | 28 269 5 |
+----------------+----------------+----------------+
| 1239 2356 4 | 568 19 68 | 125 7 129 |
| 129 8 25 | 7 4 19 | 125 3 6 |
| 19 56 7 | 56 2 3 | 14 149 8 |
+----------------+----------------+----------------+
One of R56C6 must be <6>. Therefore, R7C6 cannot be <6> and must be <8>. (Edit: Oops! I missed the elimination of <6> in R5C4!)
The only possibilities of <4> in C6 are in R56. Therefore, R56C6 cannot be <8>, and the only remaining possibility is R7C6 is <8>.
This reveals another UR on <56> in R79C24. R7C2 cannot be <56>. After further reductions, we get to:
Code: Select all
+----------------+----------------+----------------+
| 5 29b 8 | 4 6 19 | 3 12a 7 |
| 7 4 239 | 23 19 5 | 6 8 12b |
| 23 1 6 | 23 8 7 | 9 5 4 |
+----------------+----------------+----------------+
| 6 5 19 | 8 3 2 | 7 4 19 |
| 48 7 12 | 9 5 46 | 128 126 3 |
| 48 239 239 | 1 7 46 | 28 269 5 |
+----------------+----------------+----------------+
| 1239 23 4 | 6 19 8 | 5 7 129a |
| 129 8 5 | 7 4 19 | 12 3 6 |
| 19 6 7 | 5 2 3 | 4 19 8 |
+----------------+----------------+----------------+
Code: Select all
+-------------+-------------+-------------+
| 5 29c 8 | 4 6 19 | 3 12d 7 |
| 7 4 29b | 3 19a 5 | 6 8 12c |
| 3 1 6 | 2 8 7 | 9 5 4 |
+-------------+-------------+-------------+
| 6 5 19a | 8 3 2 | 7 4 19b |
| 48 7 12 | 9 5 46 | 128 126 3 |
| 48 29d 3 | 1 7 46 | 28 269 5 |
+-------------+-------------+-------------+
| 129 3 4 | 6 19b 8 | 5 7 129ad|
| 129 8 5 | 7 4 19 | 12c 3 6 |
| 19 6 7 | 5 2 3 | 4 19 8 |
+-------------+-------------+-------------+
Also, coloring on <2>, eliminates <2> from R6C7, and we get to:
Code: Select all
+-------------+-------------+-------------+
| 5 29 8 | 4 6 19b | 3 12c 7 |
| 7 4 29 | 3 19 5 | 6 8 12 |
| 3 1 6 | 2 8 7 | 9 5 4 |
+-------------+-------------+-------------+
| 6 5 19 | 8 3 2 | 7 4 19 |
| 8 7 12 | 9 5 4 | 12 6 3 |
| 4 29 3 | 1 7 6 | 8 29 5 |
+-------------+-------------+-------------+
| 12 3 4 | 6 19 8 | 5 7 129 |
| 129 8 5 | 7 4 19a | 12 3 6 |
| 19 6 7 | 5 2 3 | 4 19d 8 |
+-------------+-------------+-------------+
This solves the puzzle.
Keith