The filing system
Claim
Under the plain numbered index, every book still carries a mark taken from the 16-point badge's 1,157 legal combinations, and that mark — not its entry number — is its address.
Construction
There are two layers, and only one of them is visible on the site today.
The display layer is the plain numbered index: seven sections, entries numbered section.entry. That is what a reader sees, and book 00 describes it.
The filing layer is the 16-point badge. A badge is a nuna surrounded by a fixed set of circles with a defined set of arrangements around it. Sixteen arrangements, lettered A to P, sit around the centre tile. Two of them cannot both be active if they share an anchor circle or share a diamond; that single exclusion rule admits exactly 1,157 legal combinations, and a book's mark is one of them.
Size sets the shelf
A combination's size — how many arrangements it lights — decides which shelf it belongs to. One arrangement gives 16 marks, and those are Core Claims. Two gives 98, Explorations and Theory. Three gives 288, Datasets. Four gives 417, Models and Tools. Five gives 274, Physical World. Six gives 64, Personal Writing.
Six is the ceiling. No legal combination holds seven, so the scheme is mathematically closed and no seventh shelf can exist. The empty combination, ∅, is reserved for the index page itself.
Marks were assigned by walking each shelf's legal-combination list in order, so the first book on each shelf holds the first legal combination at that size. Slugs are the mark in lower case with /book- in front: mark A becomes /book-a, mark ACFHKN becomes /book-acfhkn.
Why the marks are not on the index
The marks were drawn as combination-shape icons, and those icons were taken off the index on purpose: a standard index reads better for now, with the possibility of bringing the shapes back later. Nothing was deleted to achieve it. The marks and slugs still exist in the data, so restoring them is a display change rather than a re-filing.
What cannot be filed here
One consequence carries over from the original scheme and is worth stating plainly: business material — NFT reasoning, print-on-demand research, pricing — has no home in this system. It belongs off-site, or in an investor-facing section.
The counts, recomputed
The sixteen arrangements and the exclusion key both live in _src/core.py. Enumerating every subset of the sixteen that breaks no exclusion, grouped by size, gives 16 · 98 · 288 · 417 · 274 · 64, summing to 1,157. Those are the six numbers in the shelf table, arrived at independently of it.
The same enumeration finds no independent set of seven, which is the ceiling claim. Book 2.9 carries the full result and the tier breakdown.
One further check falls out of it. The first legal combination at each size, in the order the enumeration produces them, is A, AC, ACF, ACFH, ACFHK, ACFHKN. Those are exactly the marks of books 2.1, 3.1, 4.1, 5.1, 6.1 and 7.1 — the first book on each shelf. That is what “walking each shelf's list in order” predicts, and it is the cheapest available test that the recorded assignments and the live enumeration are the same scheme.
70 books are filed, of 1,157 possible marks. The system is nowhere near full.
Note
Aaron's slot.
Open questions
- Where the Introduction itself sits. The display has seven sections because Introduction was split out as section 1 and the six original shelves became 2 through 7. Introduction has no shelf behind it and no marks, because combination size sets the shelf and Introduction has no size. The filing system records the choice as: if the mark layer is ever restored, Introduction either folds back in or takes the empty mark. Neither is yet workable as written — ∅ is already reserved for the index page, and there is only one of it, so it cannot address three books. The keys 00, 01 and 02 these three pages use are a placeholder outside the badge scheme, not a ruling.
- Whether the mark layer returns to the index at all, and in what form.
- The parity convention, which is a filing question as much as a geometric one: every coordinate-named dataset inherits the answer. See book 2.7.
- Whether the display sections and the original shelves are allowed to drift apart. They line up today only because the sections were built on top of the shelves.
Checks
| What | How | Source |
|---|---|---|
| Two layers, display and filing | Described in full, including that the marks and slugs still exist in the data | library-filing-system.md |
| 1,157 legal combinations | Recomputed from the sixteen arrangements and the exclusion key: 1,157 | _src/core.py |
| The six shelf capacities | Recomputed by size: 16, 98, 288, 417, 274, 64 — matching the shelf table | _src/core.py; START-HERE.md |
| Six is the ceiling | The same enumeration finds no independent set of seven | _src/core.py |
| ∅ is reserved for the index page | Stated in the handoff brief and repeated in the filing system | START-HERE.md; library-filing-system.md |
| Marks assigned by walking each shelf's list in order | Stated in the handoff brief; tested here by recomputing the first combination at each size and comparing with the first book on each shelf: A, AC, ACF, ACFH, ACFHK, ACFHKN | START-HERE.md; reference/mark-assignments.md; _src/core.py |
| Slugs are the mark in lower case, prefixed /book- | Stated under numbering | library-filing-system.md |
| Why the icons came off the index | A standard index reads better for now; nothing was deleted | library-filing-system.md |
| Business material has no home here | Stated as a consequence of the scheme in both files | START-HERE.md; library-filing-system.md |
| 70 books of 1,157 possible marks | The totals given in the filing system, and the entry count the index prints | library-filing-system.md; _src/books.py |
| Section 1's own mark | None exists. Introduction has no shelf and no size; the choice is recorded as unmade | library-filing-system.md |