Remembrances of Alan

AbstractAlan L. Selman, who profoundly shaped the eld of computational complexity and who sup- ported and encouraged students and colleagues in so many ways, died on January 22, 2021 at the age of 79. On the pages that follow are six remembrances of him and his work from people who knew him well, ranging from the personal to the technical. I'd like to thank them all profusely|Lance Fortnow, Steven Homer, Mitsu Ogihara, Ken Regan, Jin-Yi Cai, Aduri Pavan|for their contribu- tions on such short notice, and I apologize in advance for not reaching out to others, simply for lack of time.