Copyright © Kevin Stone

R3C9 is the only square in row 3 that can be <6>

R9C7 is the only square in column 7 that can be <7>

R1C9 is the only square in column 9 that can be <3>

Intersection of column 4 with block 5. The value <4> only appears in one or more of squares R4C4, R5C4 and R6C4 of column 4. These squares are the ones that intersect with block 5. Thus, the other (non-intersecting) squares of block 5 cannot contain this value.

R4C5 - removing <4> from <2458> leaving <258>

R5C5 - removing <4> from <124578> leaving <12578>

R6C5 - removing <4> from <1468> leaving <168>

Intersection of block 2 with row 2. The value <9> only appears in one or more of squares R2C4, R2C5 and R2C6 of block 2. These squares are the ones that intersect with row 2. Thus, the other (non-intersecting) squares of row 2 cannot contain this value.

R2C1 - removing <9> from <2789> leaving <278>

R2C2 - removing <9> from <1289> leaving <128>

R2C8 - removing <9> from <1259> leaving <125>

Intersection of block 6 with row 5. The value <8> only appears in one or more of squares R5C7, R5C8 and R5C9 of block 6. These squares are the ones that intersect with row 5. Thus, the other (non-intersecting) squares of row 5 cannot contain this value.

R5C1 - removing <8> from <248> leaving <24>

R5C3 - removing <8> from <28> leaving <2>

R5C4 - removing <8> from <45789> leaving <4579>

R5C5 - removing <8> from <12578> leaving <1257>

R5C1 can only be <4>

R3C5 is the only square in row 3 that can be <4>

R1C2 is the only square in row 1 that can be <4>

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

R7C7 is the only square in row 7 that can be <9>

R3C7 can only be <8>

R3C3 can only be <3>

R1C7 can only be <1>

R1C3 can only be <8>

R5C7 can only be <5>

R3C1 can only be <9>

R9C3 can only be <5>

R4C8 can only be <4>

R7C3 can only be <1>

R1C5 can only be <7>

R5C5 can only be <1>

R2C6 can only be <9>

R2C4 can only be <8>

R5C6 can only be <7>

R1C1 can only be <2>

R6C8 can only be <1>

R5C9 can only be <8>

R5C4 can only be <9>

R1C8 can only be <9>

R2C1 can only be <7>

R7C1 can only be <6>

R2C2 can only be <1>

R4C4 can only be <5>

R6C4 can only be <4>

R8C4 can only be <7>

R8C1 can only be <8>

R9C1 can only be <3>

R8C2 can only be <2>

R8C6 can only be <6>

R8C8 can only be <5>

R6C6 can only be <3>

R9C5 can only be <2>

R8C9 can only be <1>

R2C8 can only be <2>

R7C9 can only be <2>

R9C8 can only be <6>

R9C9 can only be <4>

R4C5 can only be <8>

R7C5 can only be <5>

R2C9 can only be <5>

R4C2 can only be <3>

R6C5 can only be <6>

R6C2 can only be <8>

R4C6 can only be <2>