     Sudoku Solution Path   Copyright © Kevin Stone R2C1 is the only square in row 2 that can be <7> R4C8 is the only square in row 4 that can be <6> R5C1 is the only square in row 5 that can be <4> R7C2 is the only square in row 7 that can be <3> R1C1 is the only square in row 1 that can be <3> R7C3 is the only square in row 7 that can be <2> R8C9 is the only square in row 8 that can be <1> R3C1 is the only square in column 1 that can be <2> R4C1 is the only square in column 1 that can be <8> R9C3 is the only square in column 3 that can be <6> R9C8 is the only square in column 8 that can be <3> R9C9 is the only square in row 9 that can be <4> R1C5 is the only square in row 1 that can be <4> R2C8 is the only square in row 2 that can be <4> R2C5 is the only square in row 2 that can be <1> R2C4 is the only square in row 2 that can be <2> R9C4 can only be <5> R9C1 can only be <9> R3C4 can only be <8> R2C6 can only be <9> R9C7 can only be <7> R8C1 can only be <5> R9C5 can only be <2> R2C9 can only be <8> R1C6 can only be <5> R8C2 can only be <7> R8C6 can only be <6> R8C4 can only be <3> R7C6 can only be <7> R5C6 can only be <8> R8C5 can only be <9> R5C4 can only be <6> R1C3 is the only square in row 1 that can be <8> R3C7 is the only square in row 3 that can be <5> R5C5 is the only square in row 5 that can be <3> R6C7 is the only square in row 6 that can be <8> Squares R1C9 and R7C9 in column 9 form a simple locked pair. These 2 squares both contain the 2 possibilities <69>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the column.    R5C9 - removing <9> from <259> leaving <25> Intersection of row 4 with block 4. The value <9> only appears in one or more of squares R4C1, R4C2 and R4C3 of row 4. These squares are the ones that intersect with block 4. Thus, the other (non-intersecting) squares of block 4 cannot contain this value.    R5C2 - removing <9> from <1259> leaving <125>    R5C3 - removing <9> from <179> leaving <17> Squares R5C3<17>, R5C7<19> and R5C8<179> in row 5 form a comprehensive locked triplet. These 3 squares can only contain the 3 possibilities <179>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the row.    R5C2 - removing <1> from <125> leaving <25> Squares R5C2, R5C9, R6C2 and R6C9 form a Type-1 Unique Rectangle on <25>.    R6C2 - removing <25> from <125> leaving <1> R6C8 can only be <7> R1C2 can only be <9> R5C3 can only be <7> R6C5 can only be <5> R1C9 can only be <6> R4C2 can only be <5> R3C3 can only be <1> R1C7 can only be <1> R7C9 can only be <9> R3C8 can only be <9> R5C8 can only be <1> R4C5 can only be <7> R5C2 can only be <2> R4C3 can only be <9> R5C9 can only be <5> R5C7 can only be <9> R6C9 can only be <2> R7C7 can only be <6>    