Here are some notes that I had written up either when I was trying learn things or when I was doing computations. A word of caution: These ntoes are old and never meant to be formal so most are never checked, so it is very likely that they contain errors (hopefully not very big ones). In case anyone uses the notes it is their responsibility to check if there is a problem. In case you find an error (or you have suggestions on anything) please let me know, I would greatly appreciate.

To be revised (12.11.18)