Copyright © Kevin Stone

R1C6 can only be <9>

R4C5 can only be <2>

R3C6 can only be <3>

R5C6 can only be <5>

R9C6 can only be <7>

R6C5 can only be <3>

R6C7 can only be <5>

R5C4 can only be <8>

R4C7 can only be <6>

R4C9 can only be <8>

R7C6 can only be <2>

R6C9 can only be <1>

R5C2 can only be <1>

R6C3 can only be <8>

R5C8 can only be <3>

R6C1 can only be <2>

R9C4 is the only square in column 4 that can be <3>

R9C9 can only be <5>

R1C9 can only be <2>

R3C8 can only be <8>

R1C8 can only be <5>

R2C8 can only be <7>

R3C2 is the only square in row 3 that can be <2>

R3C7 is the only square in row 3 that can be <9>

R7C7 can only be <7>

R2C9 can only be <3>

R8C7 can only be <3>

R8C9 can only be <9>

R2C7 can only be <4>

R7C2 is the only square in row 7 that can be <9>

R2C1 is the only square in row 2 that can be <9>

R7C3 is the only square in row 7 that can be <5>

R4C3 can only be <4>

R4C1 can only be <5>

R3C3 can only be <1>

R3C4 can only be <4>

R2C3 can only be <6>

R1C4 can only be <6>

R7C4 can only be <1>

R2C5 can only be <1>

R2C2 can only be <5>

R8C3 can only be <7>

R8C5 can only be <6>

R7C8 can only be <6>

R9C8 can only be <1>

R8C2 can only be <8>

R9C1 can only be <4>

R8C8 can only be <2>

R8C1 can only be <1>

R1C2 can only be <4>

R9C2 can only be <6>

R1C1 can only be <8>