Prelims
a) R1C12 = {59/68}
b) R12C9 = {19/28/37/46}, no 5
c) R3C23 = {49/58/67}, no 1,2,3
d) R34C4 = {17/26/35}, no 4,8,9
e) R9C89 = {15/24}
f) 11(3) cage at R3C9 = {128/137/146/236/245}, no 9
g) 11(3) cage at R7C1 = {128/137/146/236/245}, no 9
h) 19(3) cage at R8C1 = {289/379/469/478/568}, no 1
i) 19(3) cage at R8C7 = {289/379/469/478/568}, no 1
j) 27(4) cage at R5C9 = {3789/4689/5679}, no 1,2
1a. 45 rule on C6789 2 outies R19C5 = 3 = {12}, locked for C5
1b. Killer pair 1,2 in R9C5 and R9C89, locked for R9
1c. 45 rule on R1 3 innies R1C349 = 12 = {138/147/237/246/345} (cannot be {129} which clashes with R1C5, cannot be {156} which clashes with R1C12), no 9, clean-up: no 1 in R2C9
1d. 27(4) cage at R5C9 = {3789/4689/5679}, CPE no 9 in R8C9
2a. R3C23 = {49/67} (cannot be {58} which clashes with R1C12), no 5,8
2b. Killer pair 6,9 in R1C12 and R3C23, locked for N1
2c. 23(5) cage at R1C3 = {13478/23468} (cannot be {12578/13568/14567/23567} which clash with R1C12), no 5
2d. 23(5) cage at R1C3 = {13478/23468}, CPE no 8 in R1C12, clean-up: no 6 in R1C12
2e. Naked pair {59} in R1C12, locked for R1 and N1, clean-up: no 4 in R3C23
2f. Naked pair {67} in R3C23, locked for R3, 7 locked for N1, clean-up: no 1,2 in R4C4
2g. 6,7 of 23(5) cage only in R1C4 -> R1C4 = {67}
2h. 23(5) cage at R1C3 = {13478/23468}, 3,4,8 locked for N1
2i. R3C1 = {12} -> R45C1 = 14,15 = {68/69/78} (cannot be {59} which clashes with R1C1)
2j. R1C349 (step 1c) = {147/237/246} (cannot be {138/345} because R1C4 only contains 6,7), no 8, clean-up: no 2 in R2C9
2k. R1C4 = {67} -> no 6,7 in R1C9, clean-up: no 3,4 in R2C9
2l. 8 in N1 only in R2C123, locked for R2, clean-up: no 2 in R1C9
3a. 45 rule on N4 2(1+1) outies R3C1 + R6C4 = 8 = [17/26]
3b. Naked pair {67} in R16C4, locked for C4, clean-up: no 1,2 in R3C4
3c. Naked pair {35} in R34C4, locked for C4
3d. R1C349 (step 2j) = {147/246} (cannot be {237} = [273] which clashes with R3C1 + R6C4), no 3, 4 locked for R1, clean-up: no 7 in R2C9
3e. 3 in N1 only in R2C123, locked for R2
3f. Naked triple {124} in R1C359, locked for R1
3g. Min R6C4 = 6 -> max R6C123 = 10, no 8,9 in R6C123
4a. 45 rule on N3 2 outies R1C56 = 1 innie R3C9 + 6
4b. Max R1C56 = 10 -> max R3C9 = 4
4c. Min R1C56 = 7, R1C5 = {12} -> no 3 in R1C6
4d. 3 in R1 only in R1C78, locked for N3
4e. 45 rule on N3 3 innies R1C78 + R3C9 = 13 = {36}4/{38}2, no 1,7
4f. 7 in R1 only in R1C46, locked for N2
4g. 11(3) cage at R3C9 = {128/146/236/245} (cannot be {137} because R3C9 only contains 2,4), no 7
5a. R1C349 (step 3d) = {147/246}
5b. Consider permutations for R3C1 + R6C4 (step 3a) = [17/26]
R3C1 + R6C4 = [17] => R1C4 = 6, R1C39 = [24] => R3C9 = 2
or R3C1 + R6C4 = [26] => R3C1 = 2
-> 2 in R1C3 + R3C1, locked for N1
and 2 in R3C19, locked for R3
6a. Min R567C5 = 12 -> no 8,9 in R5C4
6b. 8 in C4 only in R789C4, locked for N8
6c. 22(4) cage at R7C4 contains 8 = {1489/2389} (cannot be {1678/2578/3478/3568} because 3,5,6,7 only in R8C5), no 5,6,7, 9 locked for N9
6d. Killer pair 1,2 in 22(4) cage and R9C5, locked for N8
6e. Min R78C6 = 8 (cannot be {34} which clashes with 22(4) cage) -> max R6C6 = 6
6f. Max R9C56 = 9 -> min R9C7 = 4
6g. 45 rule on N8 3 innies R7C56 + R8C6 = 1 outie R9C7 + 10
6g. Max R7C56 + R8C6 = 18 -> max R9C7 = 8
7a. 45 rule on N69 2 innies R49C7 = 1 outie R3C9 + 7
7b. Max R3C9 = 4 -> max R49C7 = 11
7c. Min R9C7 = 4 -> max R4C7 = 7
8a. 9 in C6 only in 22(5) cage at R2C6 = {12379/12469/13459}, no 8
8b. R1C6 = 8 (hidden single in C6), R1C78 = {36}, 6 locked for R1 and N3, R2C9 = 9 -> R1C9 = 1, placed for D/, R1C35 = [42], R9C5 = 1, clean-up: no 5 in R9C89
8c. R1C78 = {36} -> R3C9 = 4 (step 4e), R9C9 = 2, placed for D\, R9C8 = 4
8d. Naked pair {58} in R3C78, 5 locked for R3 and N3 -> R3C456 = [391], R4C4 = 5, placed for D\ -> R1C1 = 9, placed for D\, R1C2 = 5
8e. R3C1 = 2 -> R45C1 = 14 = {68}, locked for C1 and N4
8f. R1C4 = 7, R6C4 = 6, placed for D/
8g. R2C4 = 4, R3C5 = 9 -> R24C5 = 12 = [57]
8h. R5C4 = 1 (hidden single in C4) -> R567C5 = 18 = {48}6, 4 locked for C5 and N5
8i. R6C6 = 3, placed for D\ -> R78C6 = 11 = {47}
8j. R9C6 = 5 (hidden single in C6), R9C5 = 1 -> R9C7 = 7 (cage sum), R2C7 = 2 -> R2C8 = 7, placed for D/
9a. R9C1 = 3 -> R8C1 + R9C2 = 16 = [79]
9b. R2C123 = [183], 8 placed for D\, R5C5 = 4, placed for D/, R6C5 = 8, R8C2 = 2, placed for D/, R8C8 = 6, placed for D\
9c. R8C2 = 2 -> R7C12 = 9 = [54], R7C3 = 8, placed for D/
9d. R6C14 = [46] -> R6C23 = 6 = [15]
9e. R2345C6 = [6192] = 18 -> R4C7 = 4
9f. R7C89 = [93] -> R56C9 = 15 = [87]
and the rest is naked singles.