Alright here is a brief walkthrough to resolve the puzzle from the state I last posted:
- Code: Select all
*-----------------------------------------------------------------------------*
| 14 56789 3789 | 1245 678 2359 | 56 379 48 |
| 2589 47 3789 | 45 678 359 | 56 1 239 |
| 2589 56789 1347 | 145 678 359 | 48 379 239 |
|-------------------------\-------------------------/-------------------------|
| 589 145789 14789 | 37 2 6 | 48 39 3489 |
| 89 4789 4789 | 37 5 1 | 2 6 3489 |
| 3 2 6 | 9 4 8 | 1 5 7 |
|-------------------------/-------------------------\-------------------------|
| 14 14 2 | 6 3 7 | 9 8 5 |
| 6 3 5 | 8 9 4 | 7 2 1 |
| 7 89 89 | 25 1 25 | 3 4 6 |
*-----------------------------------------------------------------------------*
Dual ALS-xz: A=r1c1+r2c2+r123c3={134789}, B=r9c3={89}, x=8|9, z=9|8 => r45c3<>8|9
Y-Wing: r45c4={37}, r2c2,r5c3=4|7 => r3c3,r45c2<>4
d\: either r2c2=4 or r3c3=1 => r23c4 must have 5 => r19c4,r123c6<>5
r9c46=[25] => r1c6=2 (hidden single c6) => r1c14={14} => r1c9=8
Turbot fish: strong links of 3 in r1c38, r3c3+r4c4 => r4c8<>3 => r4c8=9
Box-line interaction: 9 on r1 locked in b1 => r23c123<>9
r5c1=9 (hidden single c1) => r5c2=8 (hidden single r5) => r9c2=9
r1c3=9 (hidden single r1,c3,b1) => r1c8=3 (hidden single r1) => r3c8=7
Pointing pair: 7 on d\ locked in r2c2+r4c4 => r4c2<>7
r4c12=[51] => r27c2=[74] => r4c4=3 => all naked singles
No chains, no colouring move. However, the 3rd line is a bit of elaborated logic, and one can argue it steps on the boundary of T&E.
I've actually proposed it as a new form of ALS in
this thread.
Half of the grid is totally empty! So what can you do next, 5 empty rows?
I could, using long contradiction chains, to prove r3c3=3 and r3c7=7 both lead to contradictions, and thus r3c3={14} and solve the puzzle. But it feels like trial and error to me.
Thanks!
