Chains and Loops

Advanced Sudoku Strategies - Chains and Loops

Forcing Chain
Generic term for any type of chain.
X-Chain
Single digit chain of cells.
XY-Chain
Chain of bivalue cells.
Remote Pairs
Simplified form of XY-Chain, involving only two digits.
Fishy Cycle| X-Cycle
Single digit continuous loop.
Broken Wing
Eliminations caused by loops of odd length.
Nice Loops
Several types of loops formed by cells following strict rules and a notation system.
Double Implication Chain| DIC
There are 2 interpretations circulating. The first originates from a reliable source [1].
A Forcing Chain that has implications in both directions.
2 Forcing Chains starting from a bivalue cell or a bilocal unit showing a verity.
Alternating Inference Chain| AIC
A chain where each node is a candidate, with alternating strong and weak inference.

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