Nice, although the derivations are a bit hard to digest for a human...<p>I still dream of a mathematical knowledge base in which one could drill down layer by layer until reaching basic axioms. Or let’s say you’re reading a proof and don’t understand how some step follows from the previous (happens frequently when reading papers in a foreign field). In this knowledge base you could increase the level of detail for that step to see a more detailed version of the derivation, sort of how you can zoom into Google Earth. Of course building such a web of mathematical knowledge would require an enormous amount of work, but maybe it could be crowdsourced like Wikipedia; e.g. someone writes a high-level proof for a theorem, and then other people could fill in the gaps in increasing levels of detail, or add references to related theorems/corollaries.