May God bless you and your...
Just adding an update. In August 2022, while giving a lecture at the IMA, at the University of Minnesota, as part of a birthday conference in honor of Gunnar Carlsson, I mentioned Donald and said he would have been quite happy to see me talk there, especially at that conference. The talk should be in the IMA archives as it was recorded. Roy Joshua, Professor, Department of Mathematics, Ohio State University, Columbus, Ohio.
Roy Joshua
January 12, 2024