What I never liked much in books that should provide knowledge.

[Albert Chan]

I think the author do this on purpose.

The prove probably don't add much to the text, and may even distract what follows.

The book is not knowledge without understanding, even if it gives the prove.
To understand this stuff, you really have to do the math, maybe a few plots.

There is no shortcut.

Just an example, while learning how strtod work, I build my own strtod-fast.c