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

The groupant beside world/src/knowledge.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/knowledge.rs`](https://github.com/ElamurAI/mova-free/blob/main/world/src/knowledge.rs)
- **source SHA-256:** `0128bd416063db7a…`
- **covers:** Supported structured perceptron correction with active witness identity (bytes 143502–144175)
- **part of:** [school-decision](https://md.groupants.elamur.ai/free/en/mova/world/src/knowledge.rs.groupant/decision.groupant/)
- **repository folder:** [`world/src/knowledge.rs.groupant/decision.groupant/witness.groupant`](https://github.com/ElamurAI/mova-free/tree/main/world/src/knowledge.rs.groupant/decision.groupant/witness.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` |
| **cost** | partial source model | [cost](#cost) |
| **descriptant** | present | [epoch-memory](#epoch-memory) |
| **invariant** | partial source model | [invariant](#invariant) |
| **tests** | existing scoped checks | [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 |
|---|---|---|---|
| `school-witness-behavior-complement` | behavior_complement | partial source model | [behavior-complement](#behavior-complement) |
| `school-witness-reverse-reconstruction` | reverse_reconstruction | partial source model | [reverse-reconstruction](#reverse-reconstruction) |
| `school-witness-coordinate-cancellation` | update_sparsity | partial source model | [coordinate-cancellation](#coordinate-cancellation) |
| `school-witness-local-gap` | energy_identity | partial source model | [local-gap](#local-gap) |

## Model text


Source-bound partial models, epoch 2026-10-29. Subject: world/src/knowledge.rs at the manifest SHA-256. Observation: Supported structured perceptron correction with active witness identity. Every relation below concerns this frozen source/configuration. Structural validation does not establish semantic correctness.

### forward

On understood non-count wrong decisions with supported right and chosen options, increment right feature coordinates and decrement chosen coordinates; otherwise keep weights.

### invariant

Only addressed ask/route/feature coordinates change; shared coordinates cancel according to multiplicity. Caller must supply valid option indexes and a valid weight table.

### cost

O(number of feature occurrences in the two support vectors); no frame search inside correction.

### checks

knowledge::school_math_tests::selected_witness_updates_the_decision_gap_and_explanation and scope_fallback_and_non_weight_decisions_do_not_learn_wrong_features. See ../../tests.md for executed scope. A proposed oracle below is not a completed check.

### epoch-memory

2026-10-29: inspected the existing implementation before modeling. Preserved current behavior, including lossy decoding, index-sensitive ties and conditional updates. Existing witness tests distinguish active-scope learning from a wrong global witness. Counts represent distinct observations, not independent proofs. No source changes, performance gain, full-course result or autonomous combiner is claimed. AST remains explicitly absent; ranges bind source bytes only. Parser resources, panic/allocation behavior and complete inference semantics remain gaps.

### behavior-complement

Type: behavior_complement. Domain and observation: Supported structured perceptron correction with active witness identity, as narrowed below. Operator/target: U is well-indexed (w,Answer,right,w') transitions without arithmetic overflow. R is learn_answer. U\R contains any w'!=w when !understood, count is Some, choice==right, or either required support is absent. In the active case it contains w'!=w+phi_right-phi_choice. This is an exact algebraic target with source-derived correspondence only.

Approximation: source-derived scoped relation, conditional on valid internal state and fixed flags/resources; unmodeled behavior remains unknown. Evidence/oracle: Existing focused fixtures exercise guard branches and active +2; no universal arithmetic proof.

### reverse-reconstruction

Type: reverse_reconstruction. Domain and observation: Supported structured perceptron correction with active witness identity, as narrowed below. Operator/target: For fixed Answer/right, w=w'-d in the active branch; otherwise w=w'. If Answer/right is hidden, B(w') is the union over all compatible d and inactive histories. Thus fixed metadata yields unique subtraction, but weights alone never identify the exercise.

Approximation: source-derived scoped relation, conditional on valid internal state and fixed flags/resources; unmodeled behavior remains unknown. Evidence/oracle: Proposed enumeration of bounded integer weights and support multiplicities.

### coordinate-cancellation

Type: update_sparsity. Domain and observation: Supported structured perceptron correction with active witness identity, as narrowed below. Operator/target: For index j, delta_j=count(right features mapped to j)-count(chosen features mapped to j). feat_idx merges Conflict slots other than Verb/Agent/Patient into coordinate12; the model uses coordinate multisets, not distinct semantic feature names.

Approximation: source-derived scoped relation, conditional on valid internal state and fixed flags/resources; unmodeled behavior remains unknown. Evidence/oracle: Existing fixture cancels shared verb in the old-witness control; noncanonical conflict collisions remain proposed.

### local-gap

Type: energy_identity. Domain and observation: Supported structured perceptron correction with active witness identity, as narrowed below. Operator/target: With fixed d and g(w)=w dot d, g(w+d)-g(w)=sum_j d_j^2. This says nothing about next-call witness selection, global held-out accuracy, or overflow. A wrong witness can improve its own gap while worsening the actually selected scope.

Approximation: source-derived scoped relation, conditional on valid internal state and fixed flags/resources; unmodeled behavior remains unknown. Evidence/oracle: Executed current-scope +2 versus old-scope -2 fixture; formal/School.lean is an external specification, not newly executed here.