---
title: "world-school-bench-scratch — Mova code model"
description: "Mova code model of world/tests/school_bench.rs: components with their labels, obernants and the model text."
url: "https://groupants.elamur.ai/free/en/mova/world/tests/school_bench.rs.groupant/scratch.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-school-bench-scratch

The groupant beside world/tests/school_bench.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/tests/school_bench.rs`](https://github.com/ElamurAI/mova-free/blob/main/world/tests/school_bench.rs)
- **source SHA-256:** `8c40dc25bc4d71e4…`
- **covers:** new allocates timestamp temp dir; command constructs CPU world binary with scratch hot/bench/missing.bin paths and two env removals. (bytes 177–819)
- **part of:** [world-school-bench](https://md.groupants.elamur.ai/free/en/mova/world/tests/school_bench.rs.groupant/)
- **repository folder:** [`world/tests/school_bench.rs.groupant/scratch.groupant`](https://github.com/ElamurAI/mova-free/tree/main/world/tests/school_bench.rs.groupant/scratch.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 | `model.md` |
| **tests** | bounded checks partial scope | [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) |
| `cpu` | cpu | partial source derived model | [cpu](#cpu) |
| `roots` | roots | partial source derived model | [roots](#roots) |
| `args` | args | partial source derived model | [args](#args) |
| `failure` | failure | partial source derived model | [failure](#failure) |

## Model text


### descriptant

#### world-school-bench-scratch

new allocates timestamp temp dir; command constructs CPU world binary with scratch hot/bench/missing.bin paths and two env removals.

##### Modeling epoch — 2026-10-31

Read full assigned source before editing; prospective predictions retained in external wave29 receipts. This child binds only its stated half-open UTF-8 byte range; other APIs remain parent scope. Evidence is limited to named bounded fixtures; registration is partial modeling. Production behavior unchanged; only inline synthetic tests added to four assigned sources.

### approximant

#### Forward relation

new allocates timestamp temp dir; command constructs CPU world binary with scratch hot/bench/missing.bin paths and two env removals.

##### Domain and resource limits

Finite valid structures and allocation-success executions under the branch conditions in models.md; integer overflow is outside measured fixtures. Exact categorical relations have no supplied percent surrogate. Macro expansion, arbitrary model quality and external effects are not inferred from syntax.

### invariant

## Invariant

No args until caller appends; missing model not created.

### Cost

One directory operation and fixed path/env allocations.

### composition

#### Composition

This scope contributes scratch to its parent. Its forward, complement and preimage are restricted to the bound byte interval. The parent syntax projection is referenced once through ../syntax.json; no independent semantic AST is claimed.

### models

### behavior_complement

Exclude model reads or binary launch during construction; other inherited settings can still affect later callers.

### reverse_reconstruction

Bench/hot roots constrain common scratch parent; equivalent configuration does not recover timestamp generation history.

### cpu

MOVA_EXEC overrides ambient GPU.

### roots

bench and hot are separate children.

### args

No plan or benchmark arguments initially.

### failure

SystemTime/create_dir unwrap; no retry on collision.

### tests

#### Bounded checks

Named checks associated with this source (not every fragment branch):

- wave29_bench_command_isolation_and_cleanup_without_spawn

17 unique named tests in total passed twice debug and twice release; sorted named outcomes equal across all four runs. Four compiled controls cover bAbI identity, StepGame tie ordering, parser-command state removal and bench-command CPU selection; each exits101 at a runtime assertion, exact source restored then positive exit0. Other sources have finite adversarial fixtures but no separately compiled mutant.

CLI integration coverage is command construction and temporary cleanup only; legacy school/model/cadence paths are not executed. No speed benchmark, GPU, live teacher, datasets or held-out replay.

Limits:

- Only command/temp helper executed; no plan/cadence/publication runtime claim
- No corpus/model/full-school; executable percent surrogate unsupported

External receipt root: $MOVA_DATA/runs/octopus-wave29-worldeval-2026-10-31.