A subject sits on a rung. Go down and you get its parts; add a rung above and it reads every rung below it, so the higher view is built from what you already saw rather than asserted over it.
Whatever you asked about is your current rung.
Open a part. You are one level more concrete.
The new level reads everything below it and says what it adds up to.
under the hoodThe ladder lives in the workspace itself; each rung is one decomposition pass.