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

The groupant beside world/src/quant.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/quant.rs`](https://github.com/ElamurAI/mova-free/blob/main/world/src/quant.rs)
- **source SHA-256:** `dd5cf73c5e8092c1…`
- **covers:** Tokenizer, precedence parser, evaluator and literal collection. (bytes 1612–4727)
- **part of:** [world-quant](https://md.groupants.elamur.ai/free/en/mova/world/src/quant.rs.groupant/)
- **repository folder:** [`world/src/quant.rs.groupant/expressions.groupant`](https://github.com/ElamurAI/mova-free/tree/main/world/src/quant.rs.groupant/expressions.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 source model | [forward](#forward) |
| **ast** | partial | `../syntax.json` |
| **composition** | partial source model | [composition](#composition) |
| **cost** | partial source model | [cost](#cost) |
| **descriptant** | partial source model | [epoch-memory](#epoch-memory) |
| **invariant** | partial source model | [invariant](#invariant) |
| **tests** | partial source model | [checks](#checks) |

## 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 |
|---|---|---|---|
| `world-quant-expressions-behavior-complement` | behavior_complement | partial source model | [behavior-complement](#behavior-complement) |
| `world-quant-expressions-reverse-reconstruction` | reverse_reconstruction | partial source model | [reverse-reconstruction](#reverse-reconstruction) |
| `world-quant-expressions-rational-oracle` | constraint_relation | partial source model | [rational-oracle](#rational-oracle) |
| `world-quant-expressions-reference-normalization` | information_loss | partial source model | [reference-normalization](#reference-normalization) |

## Model text


Tokenizer, precedence parser, evaluator and literal collection.

### forward

Sentence-prefix validation applies only to numeric literals. References read the current command-order state and carry no sentence provenance. Thus @2 set a.x=19 followed by @1 set b.x=a.x and @1 ask b.x remains green when 19 occurs only in sentence 2. This is a documented current limitation, not complete temporal provenance or a proposed behavior change.

Tokenize operators/whitespace; parse term before expression; atoms are parentheses, rationals or lowercase dotted references. eval recursively applies exact rational arithmetic; nums_of traverses literals left-to-right.

### invariant

Accepted parse consumes all tokens. Undefined references and zero divisors fail. Direct Ex::Bin with an unknown operator falls into division; the model restricts to parser-produced operators.

### cost

O(L) tokenization and O(E) node construction, recursive rational costs dependent on bit length; depth may reach O(E).

### composition

Parsing feeds ordered execution; literal collection precedes evaluation against state, and check merges parse errors, execution diagnostics and gold inequality. Text extraction is an external exact dependency. Numeric-origin errors do not suppress effects, unlike evaluation and anchor errors; a parent must preserve this distinction. Dataset/teacher adapters do not establish script semantics.

### epoch-memory

2026-10-30: regressions first demonstrated backward-anchor number leakage and destination credit from missing transfer sources. Prefix endpoints now restrict each command to its own sentence prefix while preserving incremental extraction; missing-source transfer skips effects. Diagnostic-only literal errors remain unchanged. No corpus or teacher calls.

### checks

See ../tests.md and native quant::wave8_models tests. Models are source-derived partial relations, with finite evidence rather than general proof. Syntax projection excludes macro expansion, name resolution and inferred types. No executable approximant: exact gates and categorical choices have no justified percentage metric here.

### behavior-complement

Universe: source strings and proposed parsed/evaluated results under fixed state. Trailing tokens, missing parentheses and unary minus exclude successful parsing; these form an inner absent set, not a full resource-safety model.

### reverse-reconstruction

For state s and rational r retain all accepted expressions evaluating to r. Equivalent parenthesizations and arithmetic identities produce multiple preimages; AST still loses whitespace.

### rational-oracle

For a,c in 0..8 and b in 1..8, ((a+c)/b)-c*a=(a+c-c*a*b)/b exactly. Tests compare 648 evaluations plus six malformed strings and zero division.

### reference-normalization

Case variants map to the same lowercase Ref, whereas Num retains original numeric spelling. Reverse formatting therefore has different fibers for reference and numeric atoms.