Kenneth I. Appel

I'm quite missing Ken lately. He would have loved the upsurge of interest in proof assistants in the mathematical community. The first time I ever heard about the lambda calculus was when Ken was proudly telling me about (his son) Andrew's thesis.

My day is improved by the memory of Ken. Much love Carole.

So sorry to hear of Ken's passing...my son graduated from DHS in 2012 and was privileged to work with him..Josh is now at Harvard...feel very blessed that he had the opportunity to work with such a brilliant mind...our sympathies to your family and thank you...The Bean family

In recent years, I have been making pizza for my family. Every time I make it, I think of the great parties we attended at the Appel house on Pell circle in Urbana, where Ken would make pizza for everybody - ken's pizzas me this idea. I use organic ingredients in proportions that are far more healthy than commercial pizza, so that my kids can have long lives. Thank you, Ken.

Dear Carole,
We want to express our sadness on hearing the news about your husband Ken. Upon reading Ken's obituary we also found out about your daughter Laurel. Our thoughts are with you at this difficult time. We fondly remember your family being part of our Urbana neighborhood.

My condolences to the Appel family. I was one of Dr. Appel's students at UNH and I was struggling in his class. He took the time to sit with me and never once did I feel stupid. In fact, it inspired me to complete my degree. He truly was one in a million.

My local paper in my very small town in Southern Illinois listed Professor Appel's death because of his fame in proving the four color theorem. I had Prof Appel my first semester at U of I for Honors Calculus III. He was an engaging and enthusiastic professor, who clearly loved mathematics, and probably was one reason I decided to major in mathematics. For years our mailings from the mathematics department proclaimed: "Four Colors Suffice."

I went on to law school because I was...

I worked for Prof. Appel when I was a CS graduate student at UIUC working my way through school as a unix system administrator for the Math department. He was kind and humble with a down to earth approach to his work. I fondly remember him learning PostScript and occasionally (if I wandered by his office) being asked to help him debug programs. It was a helpful example for me, a very intimated first year graduate student, to see someone so smart asking for help.

I am sorry for your family's loss. My condolences. Was Mr. Appel related to a Gunther Appel of Potsdam or Nedrow NY? I ask because Gunther was my grandfather and his mother, Ethel lived in NYC. Never knew any of his family.