The route — every concept in one order, level 0 upward
The concept map is a map: it shows the whole shape of the folder at once, which is what you want once you know where you are. This page is a road. It takes the same concepts, puts them in one order, numbers them, and hands each one a link straight to its own page — so learning this folder is a matter of starting at step 1 and pressing next.
In one line. Start at step 1, click the name, read the page, press next at the foot of it, repeat. You never have to come back here to find your place: every concept's page carries its own step number and the two concepts either side of it.
How the order is built, and why you can trust it.
Every concept in terms.json names its direct prerequisites. From those the widget computes a
level: level 0 needs nothing, and level N means N ideas stacked one on another come first.
The route is simply every level in turn — all of level 0, then all of level 1, and so on to the
deepest.
So the one guarantee this page makes is the useful one: nothing on the route ever asks you to already know something further down it. Read in this order and you are never ambushed.
Inside a level, order does not matter. Nothing on a level depends on anything else on the same level, so the concepts there can be read in any order at all. They are grouped by theme and then by how heavily the notes lean on them, because a level read as a flat line is a bag of unrelated ideas that happen to be equally deep.
Three ways to use it, depending on why you are here.
Learning the folder from nothing — start at step 1 and follow the numbers. The stepper at the foot of every concept page keeps the thread; you need never return to this page.
Learning one thing properly — find it below, open it, and read its Learn first row. Or ask directly with the worked paths, which answer before X, learn these for any concept.
Checking how deep something is — the level column is the honest difficulty measure. A concept at level 11 is not harder to state than one at level 2; it is eleven ideas further from the ground.
You met a word in a note and are lost — this page is the wrong door. Use the index, which lists every concept and every other name it goes by.
The route
Each entry is a link to that concept's own page, and the number beside it is its position in the
walk — the same number the page itself prints, because both come from one function. Any level is
linkable as learn.md#level-4, which is what the all N concepts at level 4 link on every
concept page points at.
What the route is not
It is not a syllabus, and it does not claim these are the only concepts worth reading in order. It is the dependency graph flattened, nothing more. Two consequences worth stating plainly:
A level is not a difficulty band. PDSCH sits at level 12 and has thirty prerequisites in total — 12 is how deep its deepest strand goes, not how many ideas it touches. Two concepts on the same level can be wildly different amounts of work.
The prev/next pair is a road, not a claim. A concept usually unlocks several others, and which of them comes "next" is a choice the ordering makes for you so that you always have somewhere to go. The honest picture is the branch printed underneath it on every concept page: level N → N+1, this unlocks …. Follow that instead whenever you have a reason to.
Nothing here is typed by hand. Add a concept to terms.json with its needs, and it takes its
place in the route, gets a number, and appears in the stepper of its neighbours on the next page
load. Get the prerequisites wrong and the widget says so in red on the map.
The other views
The route is one of five ways into the same registry. The other four live on the concept map:
| If you want | Go to |
|---|---|
| a road to walk, start to finish | this page |
| the whole shape at once, by level and theme | the hierarchy |
| what the folder is about — the eleven subjects | the themes |
| before X, learn these, for one concept | the worked paths |
| a word you met, and which idea owns it | the index |
| the full ledger — clause, state, level, usage | everything tracked |
And the group notes are the narrative. A route is a sequence of definitions; the eleven ref-
notes read a whole theme as one argument, and the deep notes (frame structure,
sounding, PDSCH) explain a subject well enough to work with. The route
gets you to the point where those read easily — it is not a substitute for them.