The
DNF (Dutch National Flag) problem was named by Edsger Dijkstra, who is Dutch, and is the basis for part of his famous quicksort sorting algorithm that is studied and learned in computer science courses and used in many sorting algorithms.
The
DNF has some other interesting applications, one of which is in evaluating multiple choice questions involving orderings and matchings. Details omitted and left for another time.
This approach was realized in the 1980's, used in the 1990's, and appears in of my publications from 2004 to 2008.
