---
title: "mlab-ext-nist-helpers — Mova code model"
description: "Mova code model of mlab/tests/ext_nist.rs: components with their labels, obernants and the model text."
url: "https://groupants.elamur.ai/free/en/mova/mlab/tests/ext_nist.rs.groupant/helpers.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/mlab/tests/ext_nist.rs.groupant/helpers.groupant/>

# mlab-ext-nist-helpers

The groupant beside mlab/tests/ext_nist.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:** [`mlab/tests/ext_nist.rs`](https://github.com/ElamurAI/mova-free/blob/main/mlab/tests/ext_nist.rs)
- **source SHA-256:** `82ac1127de001872…`
- **covers:** data_rows locates Data+lines header, extracts first two integers and inclusive1-based span, keeps numeric tokens. num normalizes uppercaseD. after selects first matching line with parseable token scanning right. lre equality first=>15, nonfinite q=>0, zero c uses absolute error, otherwise relative, clamp0..15. (bytes 650–3002)
- **part of:** [mlab-ext-nist](https://md.groupants.elamur.ai/free/en/mova/mlab/tests/ext_nist.rs.groupant/)
- **repository folder:** [`mlab/tests/ext_nist.rs.groupant/helpers.groupant`](https://github.com/ElamurAI/mova-free/tree/main/mlab/tests/ext_nist.rs.groupant/helpers.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` |
| **cost** | symbolic source derived | [invariant](#invariant) |
| **descriptant** | present | [descriptant](#descriptant) |
| **invariant** | partial | [invariant](#invariant) |
| **tests** | partial bounded parent 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) |
| `header_coordinates` | header_coordinates | partial source derived model | [header_coordinates](#header-coordinates) |
| `metric_zero` | metric_zero | partial source derived model | [metric_zero](#metric-zero) |
| `branch_relation` | branch_relation | partial source derived model | [branch_relation](#branch-relation) |
| `resource_cost` | resource_cost | partial source derived model | [resource_cost](#resource-cost) |

## Model text


### descriptant

#### mlab-ext-nist-helpers

data_rows locates Data+lines header, extracts first two integers and inclusive1-based span, keeps numeric tokens. num normalizes uppercaseD. after selects first matching line with parseable token scanning right. lre equality first=>15, nonfinite q=>0, zero c uses absolute error, otherwise relative, clamp0..15.

Epoch 2026-10-31: isolated source-bound fragment over bytes [650,3002); includes no claim beyond this relation. Source hash 82ac1127de001872692aa31cc92c6bf01f367afe18cfbd08941641a96851256c.

### approximant

#### helpers: forward relation

data_rows locates Data+lines header, extracts first two integers and inclusive1-based span, keeps numeric tokens. num normalizes uppercaseD. after selects first matching line with parseable token scanning right. lre equality first=>15, nonfinite q=>0, zero c uses absolute error, otherwise relative, clamp0..15.

Domain: Well-formed one-based header spans and bounded synthetic data; frozen certified datasets unexecuted.

Executable surrogate gap: no measured cheaper implementation with a useful scoped metric is supplied. Categorical/error/effect relations are exact obligations, not percent losses. Future numeric caps only1/2/5/10%.

### invariant

#### helpers: invariant and cost

A=3,B=4 selects Rust lines[2..4], retaining both endpoints.

q=.001,c=0 yields3; q=infinity,c=1 yields0; min_lre empty starts15.

Scope-specific cost: O(text bytes) parsing plus O(selected numeric tokens) storage; LRE O(1), matrix literal O(rendered bytes).

### models

### behavior_complement

Invalid span can panic; nonnumeric tokens skipped rather than rejected. Equal infinities yield15 by equality-before-finite, not a general finite accuracy claim.

### reverse_reconstruction

data_rows output admits ignored labels and whitespace and arbitrary lines outside span; LRE cap15 admits exact match and sufficiently small errors.

### header_coordinates

A=3,B=4 selects Rust lines[2..4], retaining both endpoints.

### metric_zero

q=.001,c=0 yields3; q=infinity,c=1 yields0; min_lre empty starts15.

### branch_relation

data_rows locates Data+lines header, extracts first two integers and inclusive1-based span, keeps numeric tokens. num normalizes uppercaseD. after selects first matching line with parseable token scanning right. lre equality first=>15, nonfinite q=>0, zero c uses absolute error, otherwise relative, clamp0..15.

### resource_cost

O(text bytes) parsing plus O(selected numeric tokens) storage; LRE O(1), matrix literal O(rendered bytes).

### tests

#### Evidence boundary

See ../tests.md for the actual selected source test and mutant. These tests sample the file, not every fragment branch. Invalid span can panic; nonnumeric tokens skipped rather than rejected. Equal infinities yield15 by equality-before-finite, not a general finite accuracy claim. Other branches here are source-derived and unexecuted unless the parent test explicitly calls them.