[comet]

Of course, the following question may be nonsense, but why not asking it: Is epub or mobi the "better" format? Or on which facts does that depend on?

I read at the moment a mathematical book with al lot of formulas I bought at Amazon. Of course it is a topaz. Other sellers only offer such books as pdf that is awfull for small e-reader-screens. So I wonder whether epub can do the same job as topaz.