@joshua.d.horwitz I guess there are probably multiple strategies. I would look at the innermost parentheses and work my way out from there. Eventually you come to recognize things more quickly.

You know what (assoc new-map key val) does?

Also, experiment and learn what the indentation patterns are for various forms. Note that that assoc form and the new-map below it are lined up, so you know they're elements in the same footing. Specifically there are the if-true and if-false parts of the if.

The maps are indebted the same as the fn, so you know they're all arguments to reduce.

Indented