Tosun Terzioglu contributed profoundly to my career, as he did for so many, many people.  As an instructor at Harvard in 1981, I applied to spend a year as a visitor at Middle East Technical University. Despite my lack of experience, Tosun gave me the opportunity—and what an opportunity it was. In 1984 I returned for another semester to METU and in 2006, under the sponsorship of the Turkish Mathematical Society, Tosun and I co-chaired a conference on undergraduate education in Istanbul. My colleagues at METU, some now at Sabanci University, are still among those I treasure most.

I remember Tosun vividly in the 1980s, coming to all the parties we had—-there were lots—-saying little, but somehow always making sure we were making the best use of our opportunities.  Later, as the president of Sabanci, Tosun invited a diverse group of faculty to his home, making it clear without saying a word that we should all know what each other was doing and collaborate.

Without fanfare, Tosun was a leader and visionary. He touched the lives of thousands.

Deborah Hughes Hallett

Professor of Mathematics, University of Arizona

dhh@math.arizona.edu

Adjunct Professor of Public Policy, Harvard Kennedy School

Deborah_Hughes_Hallett@Harvard.edu