Cell Forcing Net
A Cell Forcing Net — the technique traditionally listed as Cell Forcing Chain — starts from every candidate in one selected cell and follows only forced consequences. Because the source alternatives are exhaustive, a conclusion reached by every branch is unconditional.
What is a Cell Forcing Net?
A true candidate makes every weakly linked candidate false. A false candidate makes the other side of a strong inference true. False on one side of a weak inference alone proves nothing. A branch choice that is not forced cannot be treated as a consequence. Every remaining source alternative must be tested; one failed branch does not settle the source.
How to spot it
State the source proposition or exhaustive source set, then annotate every step with its reason. Compare all branches and accept only a target truth value shared by every one.
The logic
At least one source alternative is true. If each alternative implies the same target conclusion, the target conclusion holds regardless of which source is true. Optional branches must remain alternatives rather than being reported as forced links.