Last candidate 5 in H1 changed to solution Last candidate 8 in H5 changed to solution Last candidate 9 in H9 changed to solution Last candidate 3 in J2 changed to solution Last candidate 8 in A2 changed to solution Last candidate 5 in C2 changed to solution Last candidate 1 in F2 changed to solution Last candidate 4 in G3 changed to solution Last candidate 7 in H4 changed to solution Last candidate 9 in J3 changed to solution

Last candidate 2 in D2 changed to solution Last candidate 1 in G1 changed to solution

1 in D9 is last in row
1 in E5 is last in column/box

Pair: between Box 6 and Col 7:
- 4 can be removed from A7
- 4 can be removed from C7

Pair: between Box 2 and Col 6:
- 8 can be removed from D6
- 8 can be removed from F6

Line/Box Reduction: 4s in box 2 remove the following in the same box:
- 4 can be removed from B5
- 4 can be removed from B6
- 4 can be removed from C5
- 4 can be removed from C6
Last candidate 5 in B5 changed to solution Last candidate 8 in B6 changed to solution

Pair: between Box 8 and Col 4:
- 5 can be removed from D4
- 5 can be removed from E4
- 5 can be removed from F4

length=4, chain ends: E9 and F1
This proves 6 is the solution at one or possibly both ends of the chain
-6[E9]+3[E9]-3[B9]+4[B9]-4[B1]+3[B1]-3[F1]+6[F1]
- 6 can be removed from E1
- 6 can be removed from E3
- 6 can be removed from F7
- 6 can be removed from F8

(RULE 4): Uncoloured candidate 9 in A7 can see two different coloured candidates of 9 elsewhere.
(RULE 4): Uncoloured candidate 9 in F7 can see two different coloured candidates of 9 elsewhere.

WXYZ Wing Type 1: The four cells {E9,D8,E1,E3} contain in total 3/5/6/7 with the hinge on E9.
Non-Restricted candidate 5 determines the 'wing' cells (in yellow) and one of those 5s must be true. Therefore...
- 5 can be removed from D3
- 5 can be removed from E7

If A3 is not 7 then both candidates in F6 are ON so A3 must be 7
Depth: 13 len: 28
-7[A3]+7[A6]-7[C6]+2[C6]-2[C5]+9[C5]-9[C7]+9[E7]-7[E7]+7[D7]-4[D7]+4[D6]-5[D6]+5[F6]
-7[A3]+7[A6]-7[C6]+2[C6]-2[C5]+9[C5]-9[C7]+9[E7]-7[E7]+7[D7]-7[D3]+6[D3]-6[F1]+6[F6]
Last candidate 7 in A3 changed to solution Last candidate 4 in A6 changed to solution Last candidate 6 in C3 changed to solution Last candidate 8 in D3 changed to solution Last candidate 4 in D4 changed to solution

Last candidate 9 in A5 changed to solution Last candidate 4 in C1 changed to solution Last candidate 2 in C5 changed to solution Last candidate 7 in C6 changed to solution Last candidate 8 in C9 changed to solution Last candidate 6 in G5 changed to solution Last candidate 3 in G9 changed to solution Last candidate 4 in J5 changed to solution Last candidate 3 in B1 changed to solution Last candidate 4 in B9 changed to solution Last candidate 9 in C7 changed to solution Last candidate 7 in E1 changed to solution Last candidate 6 in E9 changed to solution Last candidate 6 in F1 changed to solution Last candidate 5 in F6 changed to solution

Last candidate 6 in D6 changed to solution Last candidate 5 in D8 changed to solution Last candidate 2 in E6 changed to solution Last candidate 3 in E7 changed to solution Last candidate 3 in F3 changed to solution Last candidate 4 in F7 changed to solution Last candidate 9 in F8 changed to solution Last candidate 2 in G8 changed to solution Last candidate 6 in J8 changed to solution Last candidate 6 in A7 changed to solution Last candidate 3 in A8 changed to solution Last candidate 7 in D7 changed to solution Last candidate 5 in E3 changed to solution Last candidate 9 in E4 changed to solution Last candidate 8 in F4 changed to solution Last candidate 5 in G4 changed to solution Last candidate 8 in G7 changed to solution Last candidate 2 in J4 changed to solution Last candidate 5 in J7 changed to solution