On the first generation kindle, Venn diagrams don't reproduce correctly. On Kindle for PC, some symbols (implication, equivalence, etc.) don't reproduce correctly. It's easier to read on the PC, as indicated by the optimized for large screens flag, but without the symbols, it is pretty much impossible to make sense of. So I end up with the kindle on my lap, reading the symbolic material there, and the other material on the PC. Not fun.