Multiple Static Cell Reduction Forcing Chain

With this solving technique, we will prove the following assertions:

Because the cell D2 cannot contain other values, and the results are the same, we can conclude that F7 must contain the value 2.

Each assertion is proved by a different chain of simple steps. The chains are static, which means that they do not rely on the conclusions of previous sub-chains.

The details of each chain are given below. Use the view selector below the grid to switch between the graphical illustrations of the different chains.

Chain 1: If D2 contains the value 1 then F7 must contain the value 2 (View 1):
(1) If D2 contains the value 1 then D5 cannot contain the value 1 (the value can occur only once in the col)
(2) If D5 does not contain the value 1 then E4 must contain the value 1 (only remaining position in the box)
(3) If E4 contains the value 1 then H4 cannot contain the value 1 (the value can occur only once in the row)
(4) If H4 does not contain the value 1 then H7 must contain the value 1 (only remaining position in the column)
(5) If H7 contains the value 1 then H7 cannot contain the value 4 (the cell can contain only one value)
(6) If H7 does not contain the value 4 then I7 must contain the value 4 (only remaining position in the box)
(7) If I7 contains the value 4 then I7 cannot contain the value 2 (the cell can contain only one value)
(8) If I7 does not contain the value 2 then F7 must contain the value 2 (only remaining position in the row)

Chain 2: If D2 contains the value 4 then F7 must contain the value 2 (View 2):
(1) If D2 contains the value 4 then D6 cannot contain the value 4 (the value can occur only once in the col)
(2) If D6 does not contain the value 4 then H6 must contain the value 4 (only remaining position in the row)
(3) If H6 contains the value 4 then H7 cannot contain the value 4 (the value can occur only once in the col)
(4) If H7 does not contain the value 4 then I7 must contain the value 4 (only remaining position in the box)
(5) If I7 contains the value 4 then I7 cannot contain the value 2 (the cell can contain only one value)
(6) If I7 does not contain the value 2 then F7 must contain the value 2 (only remaining position in the row)

Chain 3: If D2 contains the value 9 then F7 must contain the value 2 (View 3):
(1) If D2 contains the value 9 then D8 cannot contain the value 9 (the value can occur only once in the col)
(2) If D8 does not contain the value 9 then F8 must contain the value 9 (only remaining position in the box)
(3) If F8 contains the value 9 then F8 cannot contain the value 2 (the cell can contain only one value)
(4) If F8 does not contain the value 2 then F7 must contain the value 2 (only remaining position in the box)