The New Sudoku Players' Forum

[ronk]

Are you saying that the XY-Wing is attributed to Gaby Vanhegan? If so, then I don't think that's correct. I believed it was first described here - http://www.setbb.com/phpbb/viewtopic.php?t=63&mforum=sudoku - by Mat Newman.

The first occurrence of "y-wing" I see in that thread is here where:

Reading a little more about this, I got an implementation working for XY-wing (which I refer to as Y-wing, for simplicity, and I realise now is a short forcing chain).

[angusj]

The first occurrence of "y-wing" I see in that thread is ...

OK, so what you're saying is that gaby was the first person to call an XY-Wing a Y-Wing.

[Cec]

"I appreciate everyone's help! ... Thanks again to all of you

Thanks for the feedback turnthepage and hope your family are feeling better.
Cec