[cmath] Obituary - Alfred B. Lehman, University of Toronto

[Alan Kelm]

The Faculty of Arts and Science, University of Toronto, deeply regrets the 
death of Professor Alfred Lehman of the Department of Math and Department 
of Computer Science.

Alfred B. Lehman received his Ph.D. in 1954 from the University of 
Florida. After working at Tulane, MIT, the Case Institute, Wisconsin, 
Rensselar, and the Walter Reed Institute, he came to the University of 
Toronto in 1965. He was jointly appointed as Professor in the Departments 
of Mathematics and Computer Science.

Professor Lehman's area of expertise was discrete and combinatorial 
mathematics, specifically network and graph theory, integer optimization, 
matroids and lattices, all of which are subjects of major interest to both 
Computer Science and Mathematics. Continuing health problems caused him to 
take disability leave in his latter years, and limited his publication 
output and his ability to supervise students; however, it is the quality 
of his work that ensures his research will continue to be remembered as 
highly significant. Referee reports on his papers described his work as 
being "deep" and "brilliant". In 1991 he received the prestigious Delbert 
Ray Fulkerson Prize, jointly awarded by the American Mathematical Society 
and the Mathematical Programming Society, for solving, in great 
generality, an open problem in combinatorial algorithms that had long 
resisted solution.

Professor Lehman did not allow his health difficulties to limit his active 
mind. Even after ceasing to teach, he was a faithful participant and 
contributor to seminars in both departments. He was a gentle, modest man. 
At his memorial there was a moving tribute from the leader of this city's 
amateur radio club, who revealed that for many years Lehman had been a 
teacher and mentor to generations of amateurs who wished to participate 
and contribute to the valuable public services that these radio clubs 
still provide. Until then, even Lehman's closest colleagues had not known 
of this involvement.

Professor Lehman passed away on May 8th, 2006 in his 75th year. He is 
survived by his wife, June Mines, a brother-in-law, and nephews and 
cousins in Florida and Pennsylvania, several of whom spoke lovingly at his 
memorial service.

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