the TA haiyu is mad, he is applying to us the grading standards of grad students, every time I check my hw score I can hardly breathe. I donno why he is doing this to us, he looks like a nice guy and lectures well, but tbh I never wanna meet him again as a TA

Greene is a beast. The homework and class are thoroughly challenging, but very rewarding. Each of the midterms so far has felt like a learning experience rather than an exam. His homework extensions are clutch. The same cannot be said, however, for the TA. While I cannot personally claim to have had any negative experiences with him, I witnessed and saw proof of other students having run-ins with the TA that were, to put it plainly, very unpleasant. Perhaps he, like us, has something to learn from Greene in terms of kindness and approachability being repaid with hard work.

This class is AWESOME! I really love the HW questions he gave us. All the questions can be connected with each other and push us to think and comprehend the theory better!

His class is also easy to follow! Before taking the class, I've seen many people said that 131A is hard. Now it's my fortune to have Greene to teach us - everything is perfectly clear and he really made this class interesting!

However, as others have noted, the TA Haiyu H is my only concern for this class. I have no idea how he graded our homework but it seems like he is a human compiler that can catch every single piece of trivial bug

Professor Greene is super nice and willing to help! His lectures may be a bit fast or I'd have to go back to organize some of my notes to completely understand what he was working at. Some weeks his homework was pretty lengthy, but if you go to his OH, he will explain and walk you through the homework questions. As others mentioned, we had a TA that was a pretty harsh grader for this class, and the TA will typically grade the homework and midterms while Greene grades the final. I was a little worried going into the final about how harshly Greene grades, but I ended up doing better on the final than I did on both midterms, and his curve was pretty generous.

This class is very rewarding. I feel like I have learned so much from Professor Greene. He is a brilliant mathematician and one of the kindest people I have ever met in my life. His HW and exam problems are interesting and teach you a lot, although very time consuming. He is, however, very willing to help us on any HW or practice exam questions that we don't understand during OH. Professor Greene is a prime example of someone who genuinely cares about his students' wellbeing as well as education. He is not just repeating the material from textbooks to us, but actually wants to train us to be better mathematicians. He holds SO MANY office hours just to help us if we need it (3 times a week after class, and for HOURS every day before exams/hard hws, even held them over breaks and weekends because we wanted more time to ask questions). This online format is probably hard for him, as he does everything on paper handwritten, so lectures/OH are a camera pointed at his paper, which is hard to see sometimes. Can't blame him for it though, because he really tries his absolute best to make everything work and honestly this is such a tiny tradeoff for what you will learn from Professor Greene.
Now our TA Haiyu Huang...is the opposite of Greene. You know it's bad when people feel the need to mention him in a bruinwalk review. This guy is one of the rudest people I have ever met and the amount of annoyance he displays when students ask him questions during office hours shocks me sometimes. I won't lie, he knows his stuff, but that means nothing if he hates students, and he sure does. This stressed me out a lot because I would be afraid to ask him questions knowing how he would react, but this class is extremely difficult so I NEED extra help. His email replies are so passive aggressive (or plain aggressive) sometimes I couldn't believe my eyes. His grading is also extra harsh but I stopped checking it after a few weeks because even if I do find a mistake, emailing him and getting a scathing reply is just not worth it. Haiyu opened my eyes because I honestly did not even know that TA's are allowed act like this towards students before this quarter. If you ever have the honor of having him as your TA and he insults you to your face/over email/on gradescope when you ask for a regrade, just treat it as a rite of passage in your math career I guess.
TLDR this class is great, Greene is the GOAT, if you see Haiyu Huang listed as TA run for your life.

Greene is the goat! He can be sorta "old school" sometimes, but it's sure that he teaches very well. However, the class syllabus is a little off from the standard 131AH -- we covered waaaaaay too much topology for it to be an analysis course. We basically covered half of 121, so it's more like... 121H with some analysis. I guess it's not really a surprise to anyone tho, since he literally wrote the textbook for 121...

PS: Haiyu "yellow ocean fish" Huang is a meanie. I don't think his grading is unfair per se, but his personality is just impossible to like (he would sometimes make students in section feel quite uncomfortable to ask questions, and any of his replies to emails/inquiries all just sound very hostile). But I guess Greene saved the day by being the sweetest math grandpa ever (tied in my heart with dag :P), so oh well.

Very nice and easy-going professor! He really cares for students, and his class is always easy to follow. The HW requires much thinking, but the questions are all helpful for comprehending the class materials in depth. Definitely recommend him to everyone who wants to try 131AH!

However, as the others noted, BE CAREFULL WITH YOUR TA! This's not a joke. Our TA Haiyu is a very strict guy---with his grading scheme, a minor mistake in one analysis can ruin your entire HW grade. I admit that it's good to train students to be cautious, but it still hurts a lot.

Professor Greene and his math 131AH are both great, but be cautious about the TA Haiyu Huang, his grading is harsh as hell

Every lectures are moving very fast and all lectures are regrading to metric space which should be taught on Math 131B.