Practise: Alternating Inference Chain (AIC)
Follow the marked candidate chain. Its first and last ends test the same digit; which outside note sees both ends?
This direct drill begins on a verified alternating chain using 2/4. The visible links remove one candidate; they do not place a digit yet.
Example 1 of 4
Your turn first
Your turn first
Trace the marked chain. Which outside 2/4-note sees its two matching ends?
Remember
An AIC alternates strong and weak links. When matching endpoint candidates cover both cases, any candidate seeing both endpoints can be removed.
Put it to use
Where you will meet it
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