     Sudoku Solution Path   Copyright © Kevin Stone R5C4 can only be <5> R5C5 can only be <4> R5C6 can only be <1> R1C7 is the only square in row 1 that can be <4> R3C4 is the only square in row 3 that can be <2> R3C9 is the only square in row 3 that can be <5> R4C7 is the only square in row 4 that can be <1> R4C3 is the only square in row 4 that can be <4> R6C3 is the only square in row 6 that can be <5> R8C9 is the only square in row 8 that can be <4> R7C6 is the only square in row 7 that can be <4> R9C5 is the only square in row 9 that can be <5> R1C5 is the only square in column 5 that can be <8> R3C7 is the only square in column 7 that can be <9> R7C9 is the only square in column 9 that can be <6> R7C4 can only be <7> R7C7 can only be <3> R9C8 is the only square in block 9 that can be <8> R5C2 is the only square in column 2 that can be <8> R6C9 is the only square in row 6 that can be <8> Squares R4C5 and R6C5 in column 5 form a simple locked pair. These 2 squares both contain the 2 possibilities <67>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the column.    R2C5 - removing <67> from <3679> leaving <39> Intersection of row 2 with block 1. The value <6> only appears in one or more of squares R2C1, R2C2 and R2C3 of row 2. These squares are the ones that intersect with block 1. Thus, the other (non-intersecting) squares of block 1 cannot contain this value.    R1C2 - removing <6> from <679> leaving <79> R2C2 is the only square in column 2 that can be <6> Intersection of column 2 with block 7. The value <2> 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.    R8C1 - removing <2> from <2379> leaving <379> Intersection of block 4 with column 1. The values <269> only appears in one or more of squares R4C1, R5C1 and R6C1 of block 4. These squares are the ones that intersect with column 1. Thus, the other (non-intersecting) squares of column 1 cannot contain these values.    R2C1 - removing <9> from <1379> leaving <137>    R8C1 - removing <9> from <379> leaving <37> R2C5 is the only square in row 2 that can be <9> R8C5 can only be <3> R1C4 can only be <6> R8C1 can only be <7> R9C6 can only be <6> R9C4 can only be <9> R8C8 can only be <2> R8C2 can only be <9> R5C8 can only be <3> R9C7 can only be <7> R9C2 can only be <2> R9C3 can only be <3> R6C7 can only be <2> R5C9 can only be <9> R5C1 can only be <2> R4C9 can only be <7> R6C1 can only be <6> R1C2 can only be <7> R3C3 can only be <8> R1C6 can only be <3> R1C8 can only be <1> R3C6 can only be <7> R1C3 can only be <9> R2C8 can only be <7> R2C9 can only be <3> R2C1 can only be <1> R3C1 can only be <3> R7C3 can only be <1> R4C5 can only be <6> R6C5 can only be <7> R4C1 can only be <9> R7C1 can only be <8> [Puzzle Code = Sudoku-20190625-Hard-309611]    