My previous criticism was meant for the Kindle version. I find the hard copy invaluable. My coursework in abstract algebra was taken four decades ago and the book we used was larger and much longer. Often I wasn't sure why we were studying certain mathematical structures (they were abstract in another sense). Here the examples and the exercises along with the author's comments make exceptionally clear why the structures are important. Carrying the book around is not more troublesome than a Kindle.