Platon Sudoku · Sudoku Study
Alternating chains · Core Concepts
A chain alternates strong and weak links to pass truth constraints from node to node.
This course is adapted from Platon Sudoku App. Read the complete example here, then continue learning and practising in the app.
View on Google PlayDefinition
A chain alternates strong and weak links to pass truth constraints from node to node.
How to find it
Start with a verified strong link and check each successive link and node.
Common mistake
A drawn line is not proof. One invalid or out-of-order link breaks the chain.
Short chain
Teaching board · local candidate diagram
Observe candidates
A chain alternates strong and weak links to pass truth constraints from node to node.
Verify the condition
Start with a verified strong link and check each successive link and node.
Draw the conclusion
Strong and weak links alternate along the full candidate chain.
Long chain
Teaching board · local candidate diagram
Observe candidates
A chain alternates strong and weak links to pass truth constraints from node to node.
Verify the condition
Start with a verified strong link and check each successive link and node.
Draw the conclusion
Strong and weak links alternate along the full candidate chain.
Recognition practice
Teaching board · local candidate diagram
Recognition practice 1
Do the shown links alternate strong and weak?
Draw the conclusion
Yes
Recognition practice 2
Do the shown links alternate strong and weak?
Draw the conclusion
No
Recognition practice 3
Do the shown links alternate strong and weak?
Draw the conclusion
Yes
Recognition practice 4
Do the shown links alternate strong and weak?
Draw the conclusion
No
Recognition practice 5
Do the shown links alternate strong and weak?
Draw the conclusion
Yes
Recognition practice 6
Do the shown links alternate strong and weak?
Draw the conclusion
No
Recognition practice 7
Do the shown links alternate strong and weak?
Draw the conclusion
Yes
Recognition practice 8
Do the shown links alternate strong and weak?
Draw the conclusion
No
Recognition practice 9
Do the shown links alternate strong and weak?
Draw the conclusion
Yes
Recognition practice 10
Do the shown links alternate strong and weak?
Draw the conclusion
No
Recognition practice 11
Do the shown links alternate strong and weak?
Draw the conclusion
Yes
Recognition practice 12
Do the shown links alternate strong and weak?
Draw the conclusion
No
Practice
This course is adapted from Platon Sudoku App. Read the complete example here, then continue learning and practising in the app.
View on Google Play