Mirrored from **Sudopedia**, the Free Sudoku Reference Guide

# Triangular Connection

In Sudoku-X, the **triangular connection** technique can be stated as follows:

- 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.

Like the Double Crossover technique, the triangular connection technique can be replicated using Color Wing with two clusters, or by using the following chain:

(X): B = A - C = D

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## See Also

This page was last modified 19:54, 27 September 2007.