---
title: "mova-hard-cases-control — Mova code model"
description: "Mova code model of tools/hard-cases/src/control.rs: components with their labels, obernants and the model text."
url: "https://groupants.elamur.ai/free/en/mova/tools/hard-cases/src/control.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**

This page as HTML: <https://groupants.elamur.ai/free/en/mova/tools/hard-cases/src/control.rs.groupant/>

# mova-hard-cases-control

The groupant beside tools/hard-cases/src/control.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/hard-cases/src/control.rs`](https://github.com/ElamurAI/mova-free/blob/main/tools/hard-cases/src/control.rs)
- **source SHA-256:** `e14231ae3f04f82f…`
- **repository folder:** [`tools/hard-cases/src/control.rs.groupant`](https://github.com/ElamurAI/mova-free/tree/main/tools/hard-cases/src/control.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 | [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.

| 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) |

## Model text


### Descriptant

The lane's priority and limit share: owned PAUSE on yield_roots while a lane pager works (fresh heartbeat, non-terminal state), removed only as exact owned bytes; an uncertain lane pager stops lane and stop_roots; a generic limit-guard STOP stops the lane. Source: `tools/hard-cases/src/control.rs`.

### Forward approximant

step(now): working = #lane pagers with state not in {plan_exhausted, stopped, deadline_reached, uncertain}, heartbeat within fresh_seconds and no STOP; any lane uncertain -> STOP(lane + stop_roots), exit; stop_root STOP starting 'limit-guard' -> STOP(lane); working>0 and no PAUSE -> write marker; working=0 and PAUSE == marker -> remove.

### Invariant

A foreign PAUSE or STOP is never removed or rewritten; STOP files are only created; the guard exits after stopping on uncertainty.

### Cost

O(lane pagers + roots) file reads per poll (20 s).

### Composition

Cooperates with fish-pages PAUSE/STOP semantics and the generic pool's limit guard. Parent hard-cases.

### behavior_complement

Does not preempt an accepted attempt, prove liveness from a snapshot, resume a stopped pager or retry. Evidence status: source-derived model with finite checks, not a proof.

### reverse_reconstruction

Events are logged; the PAUSE marker names the lane root, so its owner is recoverable from the file.

### Tests

control::tests (2026-11-04): lane work pauses t06 but not the operator-paused t07; stale heartbeat and plan_exhausted remove only the owned pause; red: uncertain lane pager stops lane, generic pagers and producer; a generic limit-guard stop reaches the lane. Finite fixtures and live samples; not a proof.