Wolfgang Haken Has Died, age 94

Haken and co-author Kenneth Appel produced the first proof of the 4-color conjecture, using computers to verify portions. Haken died at his home in Illinois with many of his family in attendance for a celebration of a wedding of a granddaughter. His daughter, computer scientist Dorothea Blostein, reports that Haken was discussing mathematics with her via Zoom only 10 days ago.