Keep the main text *focused*: - include *hooks* to deeper subjects - ...but not expositions of every subject that comes up Remember, these are *nodes*: the goal is to *make the reader *aware* of the other directions*, but not explore them completely, as that is an Augean task (choice word). It's fine to include some pointers and some longer expositions (e.g., lattice theory), but do those *separately*: let 'em *drill down*.