- Code: Select all
`*-----------------------------------------------------------*`

| 689 3689 389 | 146 1346 7 | 2 5 14689 |

|N679 1 A29 | 5 8 G24 |M4679 MF46 3 |

| 5 Q23678 4 | 126 1236 9 |L67 H168 H168 |

|-------------------+-------------------+-------------------|

|C468 C468 7 |K1248' K1'24 3 | 5 9 D26 |

| 3 4689 B89 |J248 5 J248 | 1 E26 7 |

| 2 5 1 | 9 7 6 | 34 348 48 |

|-------------------+-------------------+-------------------|

|O479 P2479 6 | 3 249 124 | 8 124 5 |

| 489 23489 23589 | 2468 2469 12458 | 3469 7 12469 |

| 1 23489 23589 | 7 2469 2458 | 3469 2346 2469 |

*-----------------------------------------------------------*

ronk wrote:For the 2nd, r5c2<>4 is also a valid exclusion.

A2 = A9 - B9 = B8 - C8 = C(4&6) - D6 = E6 - F6 = F4 - G4 = G2 (- A2); closed loop => r189c3 <> 9, r5c2 <> 8, r39c8 <> 6, and r2c7 <> 4

Can you explain, because for some reason I don't see this one.

ronk wrote:For the 3rd, defining set J = {r4c5,r5c46} would simplify the expression a little.

Yeah, you caught me going a bit nuts there. Sometimes you just don't see the easiest path. Could have used strong links C8 = K8, and then between 1's in box 5 as well.

ronk wrote:In the 4th, I would've missed the r2c1<>9 exclusion. How do you think to even look for that?

L7 = L6 - M6 = N6 - N7 = O7 - P7 = Q7 (- L7); closed loop => r1c9 & r3c89 <> 6, and r2c1 <> 9

With a closed AIC loop, either one side or the other of every weak inference must be true; so you just check them all. It's pretty obvious from the bolded part of the chain that N just equals 67