But thats such a specific example. Math books have so much complex notation and wierd inline elements... he had to invent TeX for that. HTML/CSS wouldn't handle

But thats such a specific example. Math books have so much complex notation and wierd inline elements... he had to invent TeX for that. HTML/CSS wouldn't handle it. Basically for all normal texbooks you will want epub as digital format. And if you have lot of ilustrations or wierd format book then just get the printed version.