I liked this rule of elimination very much. Well explained with many examples.
Pl let us know the Video Link, where "ROW Variation" of X-Wing Technique is explained with examples.
To niilus : I guess, the FOCUS in that example @ 5:33 was to emphasize what is NOT covered by X-Wing Col Var, hence "1" was not pointed out. Others can confirm / correct this.
If I am right than in a last example you can insert 8 in row 2 column 9 , because of this X Wing rule 7 could be removed and you found that there is a 6 in a same row , right ?
If you are going to use a computer to solve a sudok, you are wasting your time. They are meant to be solved by thinking. If the computer does the thinking what is the point?
you can get a excel spreadsheet that fills automatically the cells as you enter the data
at jean.david.free.fr/sudoku-crible.xls
next you do the rest
enjoy