Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Full of errors

~I usually gave books I bought not bad reviews. But this one, I hate to put it in this way, is full of wrong concept, unclear definition, misleading explanation, incomplete proof, ... A mathmactics book like this is a real shame!The reason I did not give it one star was I like Schaum book's style: definition, then example, then exercise, then answer at the end (this one doesn't have).In sum, you can't use this book for any purpose, except as one reviewer pointed out, the errors really~~ make you think about the concept. But before you can do that, you should already know some basic abstract algebra and have a logic mind.~