There are some deep connections between machine learning, compression, and cryptography with information theory as a common thread.

Also, I’ve never seen “ass.” Used to shorten “aside” — I typically use N.B. but perhaps only for important ones.

For anyone wanting an introductory text for information theory & that explores some of these connections & applications, it's worth checking out the late David MacKay's 2003 textbook Information Theory, Inference & Learning Algorithms https://www.inference.org.uk/itila/

The "ass." more likely stands for "assuming".

3Blue1Brown has a good video about this: https://www.youtube.com/watch?v=l6DKRf-fAAM