Aligned Triple Exclusion

Aligned Triple Exclusion is a solving technique in which the solver checks combinations of digits in a triple of cells located in an intersection. It is an extension of Aligned Pair Exclusion.

Example

An example of Aligned Triple Exclusion is shown below, taken from Ruud's Daily Nightmare for 2006 November 25.

By enumerating the possible combinations of the blue cells, and striking off those combinations that conflicts with any of the yellow cells, we find that the digit 2 can be eliminated from r2c6.

Non-alignment

The enumeration technique does not require that the cells be aligned within an intersection. See Subset Exclusion.

See also

• Aligned Pair Exclusion
• Subset Exclusion
• Subset Counting