---
title: "mova-nightingale-round — Mova code model"
description: "Mova code model of tools/nightingale/src/round.rs: components with their labels, obernants and the model text."
url: "https://groupants.elamur.ai/free/en/mova/tools/nightingale/src/round.rs.groupant/"
---
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This page as HTML: <https://groupants.elamur.ai/free/en/mova/tools/nightingale/src/round.rs.groupant/>

# mova-nightingale-round

The groupant beside tools/nightingale/src/round.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:** [`tools/nightingale/src/round.rs`](https://github.com/ElamurAI/mova-free/blob/main/tools/nightingale/src/round.rs)
- **repository folder:** [`tools/nightingale/src/round.rs.groupant`](https://github.com/ElamurAI/mova-free/tree/main/tools/nightingale/src/round.rs.groupant)

> **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 | [Forward approximant](#forward-approximant) |
| **Ast** | partial | `syntax.json` |
| **Composition** | partial | [Composition](#composition) |
| **Cost** | partial | [Cost](#cost) |
| **Descriptant** | present | [Descriptant](#descriptant) |
| **Invariant** | partial | [Invariant](#invariant) |
| **Tests** | finite evidence | [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.

| relation | 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) |

## Model text


### Descriptant

The Eel's lm-<lang> round child: newest ready handoff (or a build), installed vs candidate on the frozen dev sample, the Eel's native round report. Source: `tools/nightingale/src/round.rs`.

### Forward approximant

args -> freeze dev (>= 1 000 tokens) -> candidate -> bits per token of current (or base, or the empty model) and candidate -> OUT/round.json, train.ids, dev.ids, candidate/{model.ngl, meta.json, deltas.tsv}.

### Invariant

dev_sha256 is the frozen sample's; train and dev ids are disjoint; the installed lineage measures equal (no gain without new text).

### Cost

Two model loads and two passes over the dev sample (seconds to a minute).

### Composition

Parent: nightingale.

### Behavior complement

Never writes the Eel's state; never installs. Evidence status: source-derived model with finite checks, not a proof.

### Reverse reconstruction

round.json names both lineages, the generation and the gain.

### Tests

#### Checks

tests/model.rs: first round wins against nothing, no gain with the installed lineage.
These are finite fixtures and measurements; not a proof.

## History


#### 2026-11-06 · document

##### Epoch 2026-11-06

First model, written with the source (the Nightingale: one per language under the Eel; a standard naturalness model with variety deltas).

## Provenance

- **source SHA-256:** `4a786db3b9d7542c…`
- **repository commit:** `2e25d7bfae9a`