| Let’s look at cell DP. This is another very difficult step for its sudoku reasoning is very challenging. Why do we even look at this cell? How do we know where to look in this sudoku table? The answer is actually very disappointing. There’s no way to find this cell but to cross reference all columns, rows, and boxes. We look at cell DP because we hope that cross referencing row D, column P, and right middle box would leave us with only one choice for this sudoku cell. And indeed if you do look closely at cell DP, you would see that it is at the cross roads of a column and a row that have all numbers in them, but one.
So let’s examine this sudoku theory. In row D we already have the numbers 4, 1, 2, 6, and 8. In column P we already have the numbers 4, 5, 7, and 9. At this point we don’t even have to look at the box for more numbers because we already have the numbers 1, 2, 4, 5, 6, 7, 8, and 9. The only missing number is 3. If we put in cell DP any number but 3, we would be violating one or more of sudoku’s general rules. |
