Regarding a previous review, I don't think it is entirely the professor's fault for his rating. The course is tough because there is a lot to cover in 6 weeks. I do admit that we all wished the class was curved, which it is not. The exams are timed and must be submitted correctly to receive credit. It hugely matters how helpful your TAs are since the professor does have other classes he is teaching and isn't readily available (unless it's his office hours). Be prepared to spend over 40 hours a week self-learning and practicing. Do problems in the textbook or other resources you can find. Many questions are trick questions and require a deeper understanding of the material. IF YOU WANT TO SAVE YOUR GPA DO NOT TAKE THIS CLASS! This is the first class in my academic journey in which I received a bad grade. Highly recommend exposing yourself to the material before the beginning of the term since most who did well were already acquainted with the material. The grading scheme is alright. No exams were dropped, but the lowest homework was dropped.

Always Always Always ALWAYS ALWays Always avoid this professor. Always avoid this professor. I can't emphasize enough how important to not take his class and save your GPA. This professor has HORRIBLE and RIDICULOUS grading policy.

First of all, he does not curve the score. You may say, not curving the score is not that bad right? Trust me, not for this professor. I have taken some lectures from other professors who do not curve the score, but they try to make their tests fair and make the average around 80. For Ouellette, lol, the average for the first two midterms is around 65. The average for the final is 66, but he DOES NOT CURVE the fucking score, which means almost half of the class will fail.
The worst thing is not only his grading policy, but his TA (Eric Prizomic, do remember him) . This TA does not know anything about Math. I went to his office hour once and asked about homework problems, he can't explain shit. During discussion, he even asked students for help because he didn't know how to solve the problem. And his discussion is a complete waste of time. This TA is also EXTREMELY strict on grading homework and exam problems. The only thing he knows is to follow the solutions he did himself, and if anything on your homework is different from his solution he will take points off.

131A is one of the most difficult classes among upper math classes. It is a class about proving, which means on your exam and your homework, it is hard for us to give a perfect proof during exam. They can take off points anywhere they like.
Making his students get low score seems please this professor and his horrible TA. Taking this professor's class is one of the worst decisions I have ever made during my life. Try to avoid this professor.