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

The groupant beside world/src/big.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/src/big.rs`](https://github.com/ElamurAI/mova-free/blob/main/world/src/big.rs)
- **source SHA-256:** `afe8d7cc25363ac7…`
- **covers:** E={i | allowed(place(i).book) AND high4(wrapping_mul(i,K))=bucket}; Y=E if |E|<=n else [E[floor(k*|E|/n)]]k<n. (bytes 1609–2767)
- **part of:** [world-big](https://md.groupants.elamur.ai/free/en/mova/world/src/big.rs.groupant/)
- **repository folder:** [`world/src/big.rs.groupant/sampling.groupant`](https://github.com/ElamurAI/mova-free/tree/main/world/src/big.rs.groupant/sampling.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 | [invariant](#invariant) |
| **tests** | partial bounded parent tests | [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) |
| `world_big_sampling_invariants` | world_big_sampling_invariants | partial source derived model | [world_big_sampling_invariants](#world-big-sampling-invariants) |
| `world_big_sampling_resource_cost` | world_big_sampling_resource_cost | partial source derived model | [world_big_sampling_resource_cost](#world-big-sampling-resource-cost) |
| `world_big_sampling_representation_join` | world_big_sampling_representation_join | partial source derived model | [world_big_sampling_representation_join](#world-big-sampling-representation-join) |
| `world_big_sampling_domain_partition` | world_big_sampling_domain_partition | partial source derived model | [world_big_sampling_domain_partition](#world-big-sampling-domain-partition) |

## Model text


### descriptant

#### world-big-sampling

E={i | allowed(place(i).book) AND high4(wrapping_mul(i,K))=bucket}; Y=E if |E|<=n else [E[floor(k*|E|/n)]]k<n.

##### Modeling epoch 2026-10-31

Prospective source/branch/cost hypotheses were saved externally before source edits. This partial source-derived model retains observed boundaries rather than claiming complete verification. Only domain/group runtime test; sampling, cache and external judgment source-modeled, no executable surrogate.

### approximant

#### Forward relation

E={i | allowed(place(i).book) AND high4(wrapping_mul(i,K))=bucket}; Y=E if |E|<=n else [E[floor(k*|E|/n)]]k<n.

Domain: Well-formed store; f64 integer conversion/huge lengths not proved.

No executable percent surrogate: these categorical/effect observations lack a useful approximation metric. Future supported caps1/2/5/10% need a defined domain/metric and real reference evidence; no error or speed bound is claimed.

### invariant

Store opens before books.tsv; accepted indices ascending; no sentence-length filter here.

Cost component: [cost.md](https://md.groupants.elamur.ai/free/en/mova/world/src/big.rs.groupant/sampling.groupant/#cost).

### cost

Store-wide scan and candidate allocation O(S log B+C), not O(n).

### composition

Store::place book u32 joins TSV first field; parser token-length gate follows selection.

### models

### behavior_complement

bucket16 cannot match high4. n0 iterates no output indices even though ratio infinity may be computed. Missing/invalid metadata id/group rows excluded; repeated book id last-wins.

### reverse_reconstruction

Y empty admits zero cap, no eligible indices or out-of-range bucket; nonempty Y constrains hash but not skipped text or candidate total.

### world_big_sampling_invariants

Store opens before books.tsv; accepted indices ascending; no sentence-length filter here.

### world_big_sampling_resource_cost

Store-wide scan and candidate allocation O(S log B+C), not O(n).

### world_big_sampling_representation_join

Store::place book u32 joins TSV first field; parser token-length gate follows selection.

### world_big_sampling_domain_partition

Well-formed store; f64 integer conversion/huge lengths not proved.

### tests

#### Scoped evidence

Parent selected test names: ["big::wave29_worldlearn::sample_name_domain_and_groups"]. These finite tests touch only the named behaviors, not every statement in this fragment. See [parent evidence](https://md.groupants.elamur.ai/free/en/mova/world/src/big.rs.groupant/#tests). control-big: compiled source mutation failed with exit101; source restored byte-for-byte and15positive tests passed.

Scope bytes [1609,2767) are bound to the shared parent syntax projection and full source hash. Only domain/group runtime test; sampling, cache and external judgment source-modeled, no executable surrogate.