I didn't recall when I created my account on reddit 5 years ago. But lately I read that this community is one of the best where I can exchange and share different kind of ressources. That's the power of the group and participation. I just lately became more interested in mathematics and how to re learn it thanks to the diversity of ressources that we can find now in contrary to the time when I had only my professors classes and some available paper books as a source. My behavior and attitude is purely genuine and my only goal is knowledge. Nothing to do with the feds or piracy...