Platon Sudoku · Sudoku Study
The uniqueness premise · Core Concepts
Uniqueness reasoning assumes the puzzle has one complete solution. The puzzle source must guarantee that premise.
This course is adapted from Platon Sudoku App. Read the complete example here, then continue learning and practising in the app.
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Uniqueness reasoning assumes the puzzle has one complete solution. The puzzle source must guarantee that premise.
How to find it
Before using a uniqueness technique, confirm the puzzle is promised to have one solution.
Common mistake
A local candidate sketch cannot prove uniqueness of the entire puzzle.
Worked example
Teaching board · local candidate diagram
Observe candidates
Uniqueness reasoning assumes the puzzle has one complete solution. The puzzle source must guarantee that premise.
Verify the condition
Before using a uniqueness technique, confirm the puzzle is promised to have one solution.
Draw the conclusion
A local diagram cannot prove uniqueness; the puzzle source must guarantee it.
Recognition practice
Teaching board · local candidate diagram
Recognition practice 1
The puzzle guarantees one solution. May uniqueness be used as a premise?
Draw the conclusion
Yes
Recognition practice 2
No uniqueness guarantee is given. Can this local sketch establish the premise?
Draw the conclusion
No
Recognition practice 3
The puzzle guarantees one solution. May uniqueness be used as a premise?
Draw the conclusion
Yes
Recognition practice 4
No uniqueness guarantee is given. Can this local sketch establish the premise?
Draw the conclusion
No
Recognition practice 5
The puzzle guarantees one solution. May uniqueness be used as a premise?
Draw the conclusion
Yes
Recognition practice 6
No uniqueness guarantee is given. Can this local sketch establish the premise?
Draw the conclusion
No
Recognition practice 7
The puzzle guarantees one solution. May uniqueness be used as a premise?
Draw the conclusion
Yes
Recognition practice 8
No uniqueness guarantee is given. Can this local sketch establish the premise?
Draw the conclusion
No
Recognition practice 9
The puzzle guarantees one solution. May uniqueness be used as a premise?
Draw the conclusion
Yes
Recognition practice 10
No uniqueness guarantee is given. Can this local sketch establish the premise?
Draw the conclusion
No
Recognition practice 11
The puzzle guarantees one solution. May uniqueness be used as a premise?
Draw the conclusion
Yes
Recognition practice 12
No uniqueness guarantee is given. Can this local sketch establish the premise?
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