From SudopediaJump to navigationJump to search
- Consider a digit X. Suppose a diagonal contains only two cells that has X as a candidate, call them A and B. Suppose another constraint contains only two cells that has X as a candidate, call them C and D. If A and C are peers, then we can eliminate X from any cell that is seen by both B and D.
Double crossover is a special case of Triangular Connection, where the constraint containing C and D is the other diagonal.
(X): B = A - C = D