Copyright © Kevin Stone

R5C5 can only be <7>

R6C2 can only be <3>

R7C5 can only be <2>

R2C5 can only be <6>

R9C2 is the only square in row 9 that can be <2>

R1C3 is the only square in column 3 that can be <3>

R8C6 is the only square in column 6 that can be <3>

R9C6 is the only square in column 6 that can be <4>

R1C7 is the only square in column 7 that can be <7>

R1C6 can only be <1>

R2C6 can only be <7>

R2C4 can only be <5>

R2C1 can only be <1>

R2C2 can only be <4>

R7C1 can only be <5>

R3C9 is the only square in row 3 that can be <4>

R3C7 is the only square in row 3 that can be <5>

R1C8 can only be <8>

R1C4 can only be <9>

R4C8 can only be <7>

R9C8 can only be <6>

R6C8 can only be <2>

R6C9 can only be <8>

R2C8 can only be <3>

R6C1 can only be <7>

R4C9 can only be <1>

R1C2 can only be <5>

R3C5 can only be <8>

R2C9 can only be <2>

R5C8 can only be <5>

R8C5 can only be <9>

R4C2 can only be <9>

R7C9 can only be <3>

R8C9 can only be <5>

R5C7 can only be <3>

R7C7 can only be <1>

R8C8 can only be <4>

R7C3 can only be <4>

R9C7 can only be <8>

R8C1 can only be <6>

R9C4 can only be <1>

R4C1 can only be <8>

R8C2 can only be <1>

R3C1 can only be <9>

R8C4 can only be <8>

R5C2 can only be <6>

R9C3 can only be <9>

R3C3 can only be <6>

R5C3 can only be <1>