---
title: "world-worldbook-book-writing — Mova code model"
description: "Mova code model of world/src/worldbook.rs: components with their labels, obernants and the model text."
url: "https://groupants.elamur.ai/free/en/mova/world/src/worldbook.rs.groupant/book-writing.groupant/"
---
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# world-worldbook-book-writing

The groupant beside world/src/worldbook.rs in the Mova repository: what the code computes, what it never does, how to go back from its outputs, its invariants, cost and checks.

## Facts

- **kind:** groupant_fragment
- **status:** partial source bound model
- **source:** [`world/src/worldbook.rs`](https://github.com/ElamurAI/mova-free/blob/main/world/src/worldbook.rs)
- **source SHA-256:** `541583ecec59c642…`
- **covers:** Rank key=(-distinctkeys,-cites,text), optional truncate. Subject sections then string-time then rest; notes use first3(full)/1(mini). Quote iff Source.pd, mini max90chars. Add Sources, footnotes, create directory then write; return md.len bytes. (bytes 74727–82021)
- **part of:** [world-worldbook](https://md.groupants.elamur.ai/free/en/mova/world/src/worldbook.rs.groupant/)
- **repository folder:** [`world/src/worldbook.rs.groupant/book-writing.groupant`](https://github.com/ElamurAI/mova-free/tree/main/world/src/worldbook.rs.groupant/book-writing.groupant)
- **repository commit:** `855da7bd4a7b`

> **Implementation material.** A Mova code model describes this code at one source revision: partial models, finite checks and their stated scope. It is not a reviewed general exposition, and its labels are shown as written, never raised.

## Components

| component | label | where |
|---|---|---|
| **approximant** | partial | [approximant](#approximant) |
| **ast** | partial | `../syntax.json` |
| **composition** | partial | [composition](#composition) |
| **cost** | partial | [cost](#cost) |
| **descriptant** | present | [descriptant](#descriptant) |
| **invariant** | partial | [invariant](#invariant) |
| **tests** | partial bounded parent tests | [tests](#tests) |

## Obernants

The typed relations around the forward model: the behaviour complement (what the code never does), the reverse reconstruction (every input compatible with an output) and specialised views.

| id | type | label | where |
|---|---|---|---|
| `behavior_complement` | behavior_complement | partial source derived model | [behavior_complement](#behavior-complement) |
| `reverse_reconstruction` | reverse_reconstruction | partial source derived model | [reverse_reconstruction](#reverse-reconstruction) |
| `world_worldbook_book_writing_invariants` | world_worldbook_book_writing_invariants | partial source derived model | [world_worldbook_book_writing_invariants](#world-worldbook-book-writing-invariants) |
| `world_worldbook_book_writing_resource_cost` | world_worldbook_book_writing_resource_cost | partial source derived model | [world_worldbook_book_writing_resource_cost](#world-worldbook-book-writing-resource-cost) |
| `world_worldbook_book_writing_representation_join` | world_worldbook_book_writing_representation_join | partial source derived model | [world_worldbook_book_writing_representation_join](#world-worldbook-book-writing-representation-join) |
| `world_worldbook_book_writing_domain_partition` | world_worldbook_book_writing_domain_partition | partial source derived model | [world_worldbook_book_writing_domain_partition](#world-worldbook-book-writing-domain-partition) |

## Model text


### descriptant

#### world-worldbook-book-writing

Rank key=(-distinctkeys,-cites,text), optional truncate. Subject sections then string-time then rest; notes use first3(full)/1(mini). Quote iff Source.pd, mini max90chars. Add Sources, footnotes, create directory then write; return md.len bytes.

##### Modeling epoch 2026-10-31

Prospective source/branch/cost hypotheses were saved externally before source edits. This partial source-derived model retains observed boundaries rather than claiming complete verification. Compression/outcome/brain/standalone/list/writer/mini helpers tested; build/principles/teacher/gather/site/passenger read chains unexecuted. No surrogate.

### approximant

#### Forward relation

Rank key=(-distinctkeys,-cites,text), optional truncate. Subject sections then string-time then rest; notes use first3(full)/1(mini). Quote iff Source.pd, mini max90chars. Add Sources, footnotes, create directory then write; return md.len bytes.

Domain: Nonempty ASCII-leading topic base, finite trusted fields and explicit writable output directory.

No executable percent surrogate: these categorical/effect observations lack a useful approximation metric. Future supported caps1/2/5/10% need a defined domain/metric and real reference evidence; no error or speed bound is claimed.

### invariant

Source-key metadata last-wins; full includes all source rows, mini cited-source detection heuristic. Timeline lexical not chronological. File write not atomic.

Cost component: [cost.md](https://md.groupants.elamur.ai/free/en/mova/world/src/worldbook.rs.groupant/book-writing.groupant/#cost).

### cost

O(F log F)sort with citation-set cost per comparator, section scans and full Markdown allocation; I/O failure can leave directory/partial file.

### composition

brain_body reads generated notes; write returns bytes, gather returns projected cited-line count, different units.

### models

### behavior_complement

pd=false never quotes sentence. Fourth cite hidden on each occurrence. limit0 still produces scaffold. Writer does not validate author Markdown or topic path; initial ASCII byte slicing can panic before I/O.

### reverse_reconstruction

Output permits arbitrary lower-ranked excluded facts, beyondcap citations, and unused attrs/nouns/lemmas. Reference-only note cannot reconstruct source sentence.

### world_worldbook_book_writing_invariants

Source-key metadata last-wins; full includes all source rows, mini cited-source detection heuristic. Timeline lexical not chronological. File write not atomic.

### world_worldbook_book_writing_resource_cost

O(F log F)sort with citation-set cost per comparator, section scans and full Markdown allocation; I/O failure can leave directory/partial file.

### world_worldbook_book_writing_representation_join

brain_body reads generated notes; write returns bytes, gather returns projected cited-line count, different units.

### world_worldbook_book_writing_domain_partition

Nonempty ASCII-leading topic base, finite trusted fields and explicit writable output directory.

### tests

#### Scoped evidence

Parent selected test names: ["worldbook::wave29_worldlearn::brain_projection_counts_beyond_twelve_and_stops_sources", "worldbook::wave29_worldlearn::compression_root_function_words_and_empty", "worldbook::wave29_worldlearn::list_roundtrip_and_bounded_writer_citations", "worldbook::wave29_worldlearn::mini_zero_budget_keeps_floor_and_first_note"]. These finite tests touch only the named behaviors, not every statement in this fragment. See [parent evidence](https://md.groupants.elamur.ai/free/en/mova/world/src/worldbook.rs.groupant/#tests). control-worldbook: compiled source mutation failed with exit101; source restored byte-for-byte and15positive tests passed.

Scope bytes [74727,82021) are bound to the shared parent syntax projection and full source hash. Compression/outcome/brain/standalone/list/writer/mini helpers tested; build/principles/teacher/gather/site/passenger read chains unexecuted. No surrogate.
