I met Avner when my husband Iannis was a postdoc at the University of Toronto. Whenever I would work from Iannis's office, Avner would often stop by to chat about their research. There was always a lot of laughter and references to Curb Your Enthusiasm. Avner was always friendly and smiling; it was clear that he was very well liked by all of the graduate students and postdocs in the computer science department.
One memorable day, Avner and Iannis were working on a proof on the whiteboard. The proof was so complex that they ran out of Greek letters to use as variables, so Avner, with a glint in his eye, decided they needed to invent a new symbol which he called "xona". Much laughter ensued; Avner was so pleased and amused by his invention. Several months later he recounted the story in an impromptu speech at our wedding; remembering it even now still makes me laugh.
My best wishes to Avner's family who have suffered an unthinkable loss; I hope you find the strength to heal. We will miss Avner very much.