     Sudoku Solution Path   Copyright © Kevin Stone R1C5 can only be <6> R3C7 can only be <3> R2C5 can only be <7> R3C5 can only be <1> R3C8 can only be <6> R1C8 can only be <9> R2C9 can only be <4> R2C1 can only be <6> R1C9 can only be <8> R8C7 is the only square in row 8 that can be <4> R9C6 is the only square in row 9 that can be <4> R4C2 is the only square in row 4 that can be <4> R1C1 is the only square in row 1 that can be <4> R1C2 is the only square in row 1 that can be <2> R6C5 is the only square in row 6 that can be <4> R9C2 is the only square in column 2 that can be <6> R9C7 is the only square in column 7 that can be <8> Squares R8C2 and R8C9 in row 8 form a simple locked pair. These 2 squares both contain the 2 possibilities <59>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the row.    R8C1 - removing <5> from <1258> leaving <128>    R8C3 - removing <59> from <2589> leaving <28> Intersection of row 8 with block 7. The value <8> only appears in one or more of squares R8C1, R8C2 and R8C3 of row 8. These squares are the ones that intersect with block 7. Thus, the other (non-intersecting) squares of block 7 cannot contain this value.    R7C1 - removing <8> from <12358> leaving <1235> Intersection of column 2 with block 7. The value <9> only appears in one or more of squares R7C2, R8C2 and R9C2 of column 2. These squares are the ones that intersect with block 7. Thus, the other (non-intersecting) squares of block 7 cannot contain this value.    R9C3 - removing <9> from <579> leaving <57> R9C9 is the only square in row 9 that can be <9> R8C9 can only be <5> R8C2 can only be <9> Squares R3C3 and R9C3 in column 3 form a simple locked pair. These 2 squares both contain the 2 possibilities <57>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the column.    R5C3 - removing <5> from <25689> leaving <2689>    R6C3 - removing <5> from <2569> leaving <269> Squares R7C2 and R9C3 in block 7 form a simple locked pair. These 2 squares both contain the 2 possibilities <57>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the block.    R7C1 - removing <5> from <1235> leaving <123>    R9C1 - removing <5> from <135> leaving <13> Intersection of column 7 with block 6. The values <259> only appears in one or more of squares R4C7, R5C7 and R6C7 of column 7. These squares are the ones that intersect with block 6. Thus, the other (non-intersecting) squares of block 6 cannot contain these values.    R4C8 - removing <2> from <23> leaving <3> R4C6 can only be <9> R4C7 can only be <2> R5C5 can only be <8> R7C5 can only be <9> R4C4 can only be <6> R4C3 can only be <8> R8C3 can only be <2> R8C8 can only be <1> R8C1 can only be <8> R9C8 can only be <7> R9C3 can only be <5> R7C8 can only be <2> R7C9 can only be <3> R7C1 can only be <1> R9C4 can only be <1> R3C3 can only be <7> R7C2 can only be <7> R9C1 can only be <3> R5C4 can only be <2> R7C6 can only be <5> R3C2 can only be <5> R5C1 can only be <5> R6C4 can only be <3> R6C6 can only be <7> R1C4 can only be <5> R6C9 can only be <6> R5C6 can only be <1> R6C3 can only be <9> R5C9 can only be <7> R7C4 can only be <8> R1C6 can only be <3> R5C7 can only be <9> R6C1 can only be <2> R5C3 can only be <6> R6C7 can only be <5> [Puzzle Code = Sudoku-20190712-Hard-311967]    