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

# wordgraph-graph

The groupant beside wordgraph/src/graph.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:** [`wordgraph/src/graph.rs`](https://github.com/ElamurAI/mova-free/blob/main/wordgraph/src/graph.rs)
- **repository folder:** [`wordgraph/src/graph.rs.groupant`](https://github.com/ElamurAI/mova-free/tree/main/wordgraph/src/graph.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 | [Approximant](#approximant) |
| **Ast** | partial | `syntax.json` |
| **Composition** | partial | [Composition](#composition) |
| **Cost** | partial | [Cost](#cost) |
| **Descriptant** | present | [Descriptant](#descriptant) |
| **Invariant** | partial | [Invariant](#invariant) |
| **Tests** | executed bounded checks | [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 graph file format (21 little-endian, 8-aligned sections: nodes, relation codes, forward and reverse CSR, OOV
strings, provenance) with its `Writer`, and the zero-copy reader `Graph` (an `Arc` over a memory map or a byte
buffer; `Clone + Send + Sync`) with the queries: node lookup, ranked neighbours, edge, plausibility, plausibility with
the isa back-off, and the writer's hint `rank`. Designed to be shared by threads of one process (the Owls, later).

### Approximant

open: validate magic, section table bounds, presence of all 21 sections, length agreement, monotone CSR offsets with
correct ends, edge targets < N and group relations < R. edges(n, r, d) = the group of n with code r, in stored order.
edge(h, r, d) = forward lookup in h, else reverse lookup in d. plausibility = PMI of that edge or 0.
plausibility_isa = direct PMI, else max over the first 8 isa parents p of d of 0.5·plausibility(h, r, p).
rank sorts candidates by (score desc, freq desc, node asc).

### Invariant

Every accessor reads in bounds after a successful open (offsets checked once). Quantization: PMI q = round(16·pmi)
clamped to 1..255 (monotone, error ≤ 1/32 bit within range); count q = round(8·log2 c), back-transform within 5 %.
Nodes sorted by (word, UPOS), so a word's nodes are a contiguous range. The file is never written in place.

### Cost

open O(N + G + E) checks (50 k graph: 38 MB, a CLI query 7 ms wall, 2026-11-06); node lookup O(log N) + one
dictionary probe; edges O(groups of n + bound); edge O(bound) each way; rank O(|cands|·8·bound).

### Composition

Written by `compile`; read by `eval`, the CLI, and future in-process users. Uses `rel` for codes and `extract::OOV_TAG`.

### Tests

`graph_is_shareable` (compile-time Send + Sync + Clone), `quantization_is_monotone_and_bounded`,
`corrupt_files_are_rejected` (bad magic, edge target out of range, truncation: red side).

### Behavior complement

Does not mutate, append to, or lock the file; does not verify the provenance JSON or the dictionary fingerprint
against the running binary; does not handle a file truncated after open (mmap: SIGBUS); does not disambiguate senses
beyond UPOS; returns 0 plausibility for absent pairs (no negative evidence).

### Reverse reconstruction

From query answers one recovers the stored edges, quantized PMI and approximate counts; from a 0 plausibility,
nothing (any of the absences listed in compile's model). The section layout is invertible: `Writer::finish` and
`Graph::new` are mutually consistent on all arrays (checked by the hand-built file test).

## Provenance

- **source SHA-256:** `d9eab21fc479fd36…`
- **repository commit:** `c24d02b4c83b`