---
title: "world-lessons — Mova code model"
description: "Mova code model of world/src/lessons.rs: components with their labels, obernants and the model text."
url: "https://groupants.elamur.ai/free/en/mova/world/src/lessons.rs.groupant/"
---
Elamur: [Mova](https://md.mova.elamur.ai/free/en/) · [Dictionary](https://md.dictionary.elamur.ai/free/en/) · [Research](https://md.research.elamur.ai/free/en/) · **Groupants**

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# world-lessons

The groupant beside world/src/lessons.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
- **status:** partial source bound model
- **source:** [`world/src/lessons.rs`](https://github.com/ElamurAI/mova-free/blob/main/world/src/lessons.rs)
- **source SHA-256:** `c095c4c5f7556a32…`
- **repository folder:** [`world/src/lessons.rs.groupant`](https://github.com/ElamurAI/mova-free/tree/main/world/src/lessons.rs.groupant)
- **repository commit:** `48f2e6f74146`

> **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 source model | [forward](#forward) |
| **ast** | partial | `syntax.json` |
| **composition** | partial source model | [composition](#composition) |
| **cost** | partial source model | [cost](#cost) |
| **descriptant** | partial source model | [epoch-memory](#epoch-memory) |
| **invariant** | partial source model | [invariant](#invariant) |
| **tests** | partial source model | [checks](#checks) |

## 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 |
|---|---|---|---|
| `world-lessons-behavior-complement` | behavior_complement | partial source model | [behavior-complement](#behavior-complement) |
| `world-lessons-reverse-reconstruction` | reverse_reconstruction | partial source model | [reverse-reconstruction](#reverse-reconstruction) |
| `world-lessons-coupling` | constraint_relation | partial source model | [coupling](#coupling) |

## Parts

- [world-lessons-parse](https://md.groupants.elamur.ai/free/en/mova/world/src/lessons.rs.groupant/parse.groupant/)
- [world-lessons-eval](https://md.groupants.elamur.ai/free/en/mova/world/src/lessons.rs.groupant/eval.groupant/)
- [world-lessons-render](https://md.groupants.elamur.ai/free/en/mova/world/src/lessons.rs.groupant/render.groupant/)
- [world-lessons-draw](https://md.groupants.elamur.ai/free/en/mova/world/src/lessons.rs.groupant/draw.groupant/)

## Model text


### model

## Lesson model, 2026-10-30

### forward

Supplied text -> Lesson -> seeded binding attempts -> expression answer plus filled template. Shared numeric map connects lets, conditions, answer and substitution; the selected partition determines template identity. all() and main_args add filesystem/CLI paths not executed in this slice.

### behavior-complement

U comprises bounded pure supplied-input call traces and observations. Inner complement excludes success violating any shared-map constraint, nonnegative answer gate or selected partition. Union of independent fragment complements would lose wiring constraints; no claim about opaque filesystem behavior.

### reverse-reconstruction

Compose converse relations through a shared Lesson, numeric environment and RNG trajectory. Preserve every compatible rejected-attempt trace. Drawn stores only text and answer, so neither source lesson nor partition nor latent numbers are uniquely recoverable.

### coupling

Public parse, eval, Lesson::{draw,exercises,test,exam}, Rng and Drawn support pure joins. school::lessons adapts Drawn to Problem(text,a=answer,b=0,Add), learns only exercises and scores test/exam; inspected only. A native parent join should preserve these exact text/answer pairs and validate the actual school answer projection. No teacher, parser, live course or retained-state improvement is claimed.

### invariant

Successful observations obey the declared forward relation with the same supplied state and order. Failure is explicit; no hidden label or retained-state guarantee is introduced.

### cost

Compose parse O(bytes) once and draw bounds per requested sample. No optimization proposed; checked arithmetic and i128 range operations add bounded per-operation work while preserving ordinary valid draws. No timing or speedup claim.

### composition

Evaluation and substitution share numeric bindings; field labels choose template containers. Child relations must agree on intermediate state, not merely final counts. Partial syntax binds the source; macro contents are opaque.

### epoch-memory

Initial review predicted arithmetic overflow and finite-pool boundary failures. Old native code failed six named witnesses: overflow, empty templates, name exhaustion, full-width range, reversed range and seed overflow. Narrow repairs retain public signatures; finite observations do not establish arbitrary-input totality. See file evidence.md for hashes and repeated results.

### checks

Eight wave12_models tests plus two existing lesson tests. Independent 19 by 19 by 7 arithmetic cases, precedence/eager failure literals, partition/substitution fixtures and exactly 2000 rejected RNG draws. Runtime guard mutations must fail named assertions. Evidence is finite; no whole-world or live course claim.

### evidence

#### Native lesson evidence, 2026-10-30

External raw logs: $MOVA_DATA/runs/octopus-wave12-lessons-2026-10-30/.

Ten focused lessons:: tests pass twice in debug and twice in release; normalized named results are identical. Eight new wave12_models tests include 2527 finite arithmetic cases. Six old-code boundary witnesses fail. A compiled production + to - mutant fails arithmetic_finite_oracle at an equality assertion; exact source restoration passes all ten tests.

No live parser, teacher, course, held-out assessment, persistence or whole-world lint execution. Recursive expression depth and arbitrary number-formatting limits are not repaired or certified. Syntax is a deterministic partial projection; macro bodies are opaque.

SHA-256 bindings:

- old-all.log: a42e9bfda3e8d6b5d4bda4c4f7acee521b3f30f52fcd7004e41ecf5a49c73af0
- debug1.log: 21a84e9bca8bbf6809d218d4c93495f58c4b18419b2466e45a06dd8db642b91a
- debug2.log: e9d75ab80a0a8f17437fdadb360d8b3e02e5ca92cc75f32deef59f219f4dc8b2
- release1.log: 885d999a0990545056963c39f95af4541537f014f65ebc02a2d60324cbaa3f7c
- release2.log: 07afe7ffe27b95be0a55294dba99134b5dfd933963338227f7ff351a9c3cf7ce
- debug1.named: f7bb5914a007c77e8e877df331a496c9242ef0c255b9d11630bad81a7abea695
- mutant.log: ea3d7a8435d4ed7680a2a8eda926ac0048189ee6dd30d31b582e2e4cc013345c
- restored.log: d4ecd8f60de883342afb3f685b2674072566501435f8949757407c054d0de017