Platon Sudoku · Sudoku Study
Strong links · Core Concepts
The two ends cannot both be false: if one is false, the other must be true. Bilocations and bivalue cells can provide this relation.
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
The two ends cannot both be false: if one is false, the other must be true. Bilocations and bivalue cells can provide this relation.
How to find it
Verify that a digit has only two positions in a region, or a cell has only two candidates.
Common mistake
Seeing each other is insufficient. A third possibility allows both ends to be false.
Row
Teaching board · local candidate diagram
Observe candidates
The two ends cannot both be false: if one is false, the other must be true. Bilocations and bivalue cells can provide this relation.
Verify the condition
Verify that a digit has only two positions in a region, or a cell has only two candidates.
Draw the conclusion
The marked region or cell has exactly two possibilities, so its ends cannot both be false.
Column
Teaching board · local candidate diagram
Observe candidates
The two ends cannot both be false: if one is false, the other must be true. Bilocations and bivalue cells can provide this relation.
Verify the condition
Verify that a digit has only two positions in a region, or a cell has only two candidates.
Draw the conclusion
The marked region or cell has exactly two possibilities, so its ends cannot both be false.
Box
Teaching board · local candidate diagram
Observe candidates
The two ends cannot both be false: if one is false, the other must be true. Bilocations and bivalue cells can provide this relation.
Verify the condition
Verify that a digit has only two positions in a region, or a cell has only two candidates.
Draw the conclusion
The marked region or cell has exactly two possibilities, so its ends cannot both be false.
Cell
Teaching board · local candidate diagram
Observe candidates
The two ends cannot both be false: if one is false, the other must be true. Bilocations and bivalue cells can provide this relation.
Verify the condition
Verify that a digit has only two positions in a region, or a cell has only two candidates.
Draw the conclusion
The marked region or cell has exactly two possibilities, so its ends cannot both be false.
Recognition practice
Teaching board · local candidate diagram
Recognition practice 1
Do the highlighted ends form a strong link?
Draw the conclusion
Yes
Recognition practice 2
Do the highlighted ends form a strong link?
Draw the conclusion
No
Recognition practice 3
Do the highlighted ends form a strong link?
Draw the conclusion
Yes
Recognition practice 4
Do the highlighted ends form a strong link?
Draw the conclusion
No
Recognition practice 5
Do the highlighted ends form a strong link?
Draw the conclusion
Yes
Recognition practice 6
Do the highlighted ends form a strong link?
Draw the conclusion
No
Recognition practice 7
Do the highlighted ends form a strong link?
Draw the conclusion
Yes
Recognition practice 8
Do the highlighted ends form a strong link?
Draw the conclusion
No
Recognition practice 9
Do the highlighted ends form a strong link?
Draw the conclusion
Yes
Recognition practice 10
Do the highlighted ends form a strong link?
Draw the conclusion
No
Recognition practice 11
Do the highlighted ends form a strong link?
Draw the conclusion
Yes
Recognition practice 12
Do the highlighted ends form a strong link?
Draw the conclusion
No
Recognition practice 13
Do the highlighted ends form a strong link?
Draw the conclusion
Yes
Recognition practice 14
Do the highlighted ends form a strong link?
Draw the conclusion
No
Recognition practice 15
Do the highlighted ends form a strong link?
Draw the conclusion
Yes
Recognition practice 16
Do the highlighted ends form a strong link?
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