Mathematical notation is not readable, no. It requires extensive training to be able to understand it, and even experts will take quite a while to comprehend a document they are not already mostly familiar with. It is not like you cross some threshold and immediately become able to understand all mathematical notation with equal ease. There's plenty of evidence for this; recently we had this quote about the ABC theorem: "It can require a huge investment of time to understand a long and sophisticated proof, so the willingness by others to do this rests not only on the importance of the announcement but also on the track record of the authors" (http://www.nature.com/news/proof-claimed-for-deep-connection...)

Other examples that highlight how understanding of mathematical research involves much more than just reading: https://docs.google.com/viewer?a=v&q=cache:5NM3XjxAWfUJ:... http://math.stackexchange.com/questions/13460/how-to-read-a-...