     Sudoku Solution Path   Copyright © Kevin Stone R4C2 can only be <1> R6C4 can only be <1> R6C6 can only be <6> R7C9 can only be <4> R4C4 can only be <9> R6C8 can only be <3> R4C6 can only be <8> R6C2 can only be <4> R4C8 can only be <6> R5C5 can only be <4> R5C9 can only be <9> R5C7 can only be <1> R5C8 can only be <8> R9C9 can only be <3> R1C1 is the only square in row 1 that can be <3> R2C8 is the only square in row 2 that can be <4> R5C2 is the only square in row 5 that can be <3> R7C5 is the only square in row 7 that can be <1> R7C2 is the only square in row 7 that can be <2> R8C7 is the only square in row 8 that can be <6> R9C3 is the only square in row 9 that can be <1> R9C5 is the only square in row 9 that can be <8> R8C3 is the only square in row 8 that can be <8> R2C7 is the only square in column 7 that can be <5> R5C3 is the only square in column 3 that can be <5> R5C1 can only be <6> Squares R1C3 and R1C9 in row 1 form a simple locked pair. These 2 squares both contain the 2 possibilities <26>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the row.    R1C5 - removing <26> from <2679> leaving <79> Intersection of block 8 with row 8. The values <237> only appears in one or more of squares R8C4, R8C5 and R8C6 of block 8. These squares are the ones that intersect with row 8. Thus, the other (non-intersecting) squares of row 8 cannot contain these values.    R8C2 - removing <7> from <579> leaving <59>    R8C8 - removing <7> from <579> leaving <59> Intersection of column 2 with block 1. The value <7> only appears in one or more of squares R1C2, R2C2 and R3C2 of column 2. These squares are the ones that intersect with block 1. Thus, the other (non-intersecting) squares of block 1 cannot contain this value.    R3C1 - removing <7> from <579> leaving <59> Squares R3C1<59>, R3C2<579> and R3C8<79> in row 3 form a comprehensive locked triplet. These 3 squares can only contain the 3 possibilities <579>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the row.    R3C5 - removing <79> from <2679> leaving <26> Squares R3C8 and R9C1 form a remote locked pair. <79> can be removed from any square that is common to their groups.    R3C1 - removing <9> from <59> leaving <5> R7C1 can only be <7> R7C8 can only be <5> R9C1 can only be <9> R8C8 can only be <9> R8C2 can only be <5> R3C8 can only be <7> R9C7 can only be <7> R1C7 can only be <9> R1C5 can only be <7> R3C2 can only be <9> R8C5 can only be <2> R2C4 can only be <3> R2C6 can only be <2> R8C4 can only be <7> R2C3 can only be <6> R8C6 can only be <3> R3C5 can only be <6> R2C2 can only be <7> R3C9 can only be <2> R2C5 can only be <9> R1C9 can only be <6> R1C3 can only be <2> [Puzzle Code = Sudoku-20190416-VeryHard-324417]    