Winter 2021 - As the person above mentioned, Visan is a really great lecturer. She's extremely clear and thorough during lectures, and goes at a comfortable pace (for the most part of the quarter). Her homework assignments are very challenging, but it really does help you understand the concepts. Plus, if you're stuck, she'll practically go through the solution with you in office hours. This class is supposed to be one of the most challenging undergrad classes in the math department, so most of the difficulty in the class should be expected. That being said, I thought her midterms were pretty reasonable and straightforward; all the points I lost were due to dumb mistakes. However, her final was more difficult (for me at least), although she did warn us about it. All in all, Visan's great, but expect to put in a lot of work into this class.