You have to give them a way of focusing on one level of abstraction at a time.

Very true. Though having levels of syntax can actually help with this, such as python's indentation. The boilerplate of if and for helps beginners to recognize it.

In contrast, I've seen Group Theory notation with juxtiposition for both function application and composition, distinguishing functions and variables by alphabet and inference. It's very compact and elegant, but hard to read at first.