Code: Select all
35 45 9 2 47+ 6 37- 1 8
34 7 18 19 5 148 39 6 2
28 126 1268 179 3 1789 4 79+ 5
6 29 27- 3 1 5 79+ 8 4
1 3 4 6 8 79+ 2 5 79-
578 59 578 4 79 2 6 3 1
9 146 3 5 2 17 8 47 67+
47 8 17* 179+ 6 13479 5 2 379*
257 2456 2567 8 479 37 1 479 367*
A. r4c7 = 7 ==> r3c8 = 7 ==> r1c5 = 7 ==> r5c6 = 7 ==> r8c4 = 7
Also, r3c8 = 7 & r5c6 = 7 ==> r7c9 = 7
B. r4c7 <> 7 ==> r1c7 = 7 & r4c3 = 7 & r5c9 = 7
See the + and - signs in the grid above to see how this works. After making the eliminations of "7" the rest of the puzzle is easily solved.
Here's my question. Is this some species of "fish"? In a way this looks like a fishy pattern, but it's not quite as simple as tracing out a binary chain. One of the "colors" (the + signs) is mapped out sort of like a Nishio move -- the other "color" is just a regular binary chain. Anyway, I've been able to spot patterns like this in quite a few puzzles, but I have no idea what it ought to be called. dcb