John Gray

John Gray

URBANA – John Walker Gray died May 17, 2017, at age 85. It was not unexpected.

He died as he lived, in a comfortable and well-planned manner, his needs anticipated, and care taken that his affairs be in order. He was there for my first breath, and I was there for his last, as is good and right. His foresight gave him, at the end of his time, an interval of rest and contentment that all deserve, but few are afforded.

Born to a merchant, he imagined for himself a life of the mind. Through hard work and patient dedication, he made that a reality, becoming an erudite and well-traveled man, a talented pianist and a mathematician of note in several fields. The arc of his life was a work of his own devising, and it was good.

John went from an undergraduate degree from Swarthmore College in 1953 to his doctorate from Stanford University in 1957 as a student of the renowned Charles Loewner. His doctoral thesis on contact structures, published in the Annals of Mathematics, remains of interest today, having been cited nearly a hundred times in recent years alone.

As a professor of mathematics at the University of Illinois, John supervised five Ph.D. students and at the end of his career served as director of graduate studies. His research interests centered on category yheory, a study of patterns common to many parts of mathematics including algebra, topology, logic and computer science. His 1974 book on formal category theory has long been a standard reference. John contributed to categorical semantics of programming languages, including versions of the lambda calculus, and he attracted several of the founders and early employees of Wolfram Research to Urbana. He made his mark, advanced the art, and his students take a part of him into the future.

John was preceded in death by his wife of many years, Eva Wirth Gray, who introduced him to Switzerland where he spent happy sabbatical years and where his only daughter, Elizabeth, died at age 15. Of his siblings, Corinne, Suzanne and Nancy, only the last survives him, as do his nephews Allen, Tom and Kayvon. Yiling, Laur and Tony preceded him in death. Of his own, he is survived by his sons, Stephen and Theodore; and three grandchildren, Addie, Emma and Connor. He is also survived by all but one of a dedicated group of caregivers who became his second family late in life. To this family - Brittany, Mary, Jan, Ashley and the tragically departed Tiffany - his first family extends their most heartfelt thanks for the love and care he received right up until the last moment of his life.

John Walker Gray executed the story of his life well and completed it with grace. He will be missed by all who knew him.