In this commit I fix a typo.
And I also take the chance to ask where the font is defined.
I expected a \usepackage{tgpagella} somewhere in cls or tex files.
Thanks! For some reason, it is correct in our Algorithms for Optimization book, but somehow the a got dropped in this repo. The font is included through the inclusion of the tufte-book.cls, which calls this file. See line 308.
In this commit I fix a typo. And I also take the chance to ask where the font is defined. I expected a \usepackage{tgpagella} somewhere in cls or tex files.