Term

• row - a single row
• column - a single column
• square - a single cell
• 3Row - a group of 3 rows; rows 1-3, 4-6, or 7-9
• 3Column - a group of 3 columns; columns 1-3, 4-6, or 7-9

• 9Square - a square of 9 cells with a bold border

• Pair-across
  • Find 2 rows in a 3Row with a shared value. Check the 3rd row of the 3Row in all its 3Squares to see if you can find a square for the 3rd instance of the shared value.
  • Repeat for all 3Row and 3Column.
• 2 squares remain
  • In a 3Square, when only two empty squares remain, ask yourself what 2 values remain. See if only one legit mapping of those values to empty squares exists.
  • Ditto for a row with only two squares remaining.
  • Ditto for a column with only two squares remaining.