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Elimination

EliminationSTEP 0/2

Introduction

It's time for a fundamental technique: Process of Elimination. When the board gets tight, the key to success is not looking for the right digit, but:

Gradual exclusion of digits that definitely cannot be there
Using notes to control the remaining options

By eliminating impossible scenarios, whatever remains - however improbable it may sound - must be the truth.

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EliminationSTEP 1/2

Note analysis

Look at the highlighted cell and the small note digits entered in it. The game also highlighted the associated row, column and 3x3 block:

Notice what large, certain digits are already in the lines intersecting this field
Compare them with the list of small notes in our cell

Each large digit in this "cross" automatically crosses out a digit from the notes.

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EliminationSTEP 2/2

Cleaning notes

We will apply the process of elimination. We reject all digits used in the highlighted cells from the notes, i.e.:

We will eliminate positions that overlap with the row, column or block
Note that after crossing out the impossible options, only one digit remains on the battlefield

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