Platon Sudoku · Sudoku Study

Candidate elimination · Core Concepts

A placed digit removes that digit from every empty cell that sees it.

This course is adapted from Platon Sudoku App. Read the complete example here, then continue learning and practising in the app.

Definition

A placed digit removes that digit from every empty cell that sees it.

Start at a placed value and inspect matching candidates in its row, column and box.

The placed digit must see the target. A conflict between unresolved candidates alone does not choose one to remove.

Teaching board · local candidate diagram

Observe candidates

A placed digit removes that digit from every empty cell that sees it.

Verify the condition

Start at a placed value and inspect matching candidates in its row, column and box.

Draw the conclusion

The placed digit shares the marked region with the target candidate, so that candidate can be removed.

Teaching board · local candidate diagram

Observe candidates

A placed digit removes that digit from every empty cell that sees it.

Verify the condition

Start at a placed value and inspect matching candidates in its row, column and box.

Draw the conclusion

The placed digit shares the marked region with the target candidate, so that candidate can be removed.

Teaching board · local candidate diagram

Observe candidates

A placed digit removes that digit from every empty cell that sees it.

Verify the condition

Start at a placed value and inspect matching candidates in its row, column and box.

Draw the conclusion

The placed digit shares the marked region with the target candidate, so that candidate can be removed.