John R Schmitt          Professor of Mathematics      Department of Mathematics       Middlebury College       Warner Hall       Middlebury, VT 05753, USA          Phone:1- 802-443-5952                        E-mail: jschmitt@middlebury.edu            Office: Warner Hall 311          Office Hours: (Spring 2021) Monday 1:45pm -- 2:45pm, Wednesday 1:30--3pm, Thursday 3:45--5pm (both in-person and via Zoom), when my office door is open and by arrangement