TA课程的老师写的可爱教材

这门课的教材之一是他自己写的新书《Tools of the Trade: Introduction to Advanced Mathematics》，封底上他的照片：（Paul Sally，一个双腿都是假肢并且少了一只眼睛的75岁传奇老头，更多8g见http://www.boston.com/yourlife/health/articles/2007/10/01/the_powerhouse_pirate_of_the_math_classroom/）

注意看每一段证明结束末尾的证毕符号：

另外刚刚不小心在wikipedia上介绍他的页面上看到的：

He is known to detest cell phones in class and has destroyed several over the years by inviting students to stomp on them or by throwing them out of a window.

看来我要小心了...-_-...