### Dead End, but not really: Demonstration that any logical chain analysis is just trial and error and that "bifurcation" is just the beginning

Shown below is the configuration part way through the Sudoku Assistant analysis of this puzzle from the top95 collection:
```920300008006408090830500000000200080709005000002006004008000010001000402200700809

92.|3..|..8
..6|4.8|.9.
83.|5..|...
---+---+---
...|2..|98.
7.9|1.5|...
..2|9.6|..4
---+---+---
4.8|6..|.1.
..1|85.|4.2
2..|7..|8.9

```

`   |---c1--|---c2--|---c3--||---c4--|---c5--|---c6--||---c7--|---c8--|---c9-- ----------------------------------------------------------------------------- r1 |     9 |     2 |     7 ||     3 |     6 |     1 ||     5 |     4 |     8    |       |       |       ||       |       |       ||       |       |       ---+-------+-------+-------||-------+-------+-------||-------+-------+------- r2 |    15 |    15 |     6 ||     4 |    27 |     8 ||   237 |     9 |    37    |       |       |       ||       |       |       ||       |       |       ---+-------+-------+-------||-------+-------+-------||-------+-------+------- r3 |     8 |     3 |     4 ||     5 |   279 |   279 ||  1267 |   267 |   167    |       |       |       ||       |       |       ||       |       |       ===========================||=======================||======================= r4 | 13456 |  1456 |    35 ||     2 |  3479 |  3479 || 13679 |     8 | 13567    |       |       |       ||       |       |       ||       |       |       ---+-------+-------+-------||-------+-------+-------||-------+-------+------- r5 |     7 |  1468 |     9 ||    18 |   348 |     5 ||  1236 |   236 |   136    |       |       |       ||       |       |       ||       |       |       ---+-------+-------+-------||-------+-------+-------||-------+-------+------- r6 |   135 |   158 |     2 ||   189 |  3789 |     6 ||  1379 |   357 |     4    |       |       |       ||       |       |       ||       |       |       ===========================||=======================||======================= r7 |   346 |    79 |     8 ||    69 |  2359 |  2349 ||   367 |     1 |  3567    |       |       |       ||       |       |       ||       |       |       ---+-------+-------+-------||-------+-------+-------||-------+-------+------- r8 |   356 |    79 |     1 ||   689 |  3589 |    39 ||     4 |  3567 |     2    |       |       |       ||       |       |       ||       |       |       ---+-------+-------+-------||-------+-------+-------||-------+-------+------- r9 |     2 |   456 |    35 ||     7 |     1 |    34 ||     8 |    36 |     9    |       |       |       ||       |       |       ||       |       |       -----------------------------------------------------------------------------`