---
title: "roundtrip-layer-residuals — Mova code model"
description: "Mova code model of models/roundtrip-layer-residuals.groupant: components with their labels, obernants and the model text."
url: "https://groupants.elamur.ai/free/en/mova/models/roundtrip-layer-residuals.groupant/"
---
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# roundtrip-layer-residuals

The groupant beside models/roundtrip-layer-residuals.groupant 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_group
- **status:** partial descriptive instance
- **bound sources:** 9
- **repository folder:** [`models/roundtrip-layer-residuals.groupant`](https://github.com/ElamurAI/mova-free/tree/main/models/roundtrip-layer-residuals.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 | [forward](#forward) |
| **ast** | not materialized |  |
| **composition** | partial | [composition](#composition) |
| **cost** | symbolic source derived | [cost](#cost) |
| **descriptant** | present | [descriptant](#descriptant) |
| **invariant** | partial | [invariant](#invariant) |
| **tests** | see source local evidence | [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 |
|---|---|---|---|
| `behavior-complement` | behavior_complement | partial source derived model | [behavior-complement](#behavior-complement) |
| `reverse-reconstruction` | reverse_reconstruction | partial source derived model | [reverse-reconstruction](#reverse-reconstruction) |
| `head-coordinate-transport` | representation_transport | partial source derived model | [head-coordinate-transport](#head-coordinate-transport) |
| `decoder-state` | state_compatibility | partial source derived model | [decoder-state](#decoder-state) |
| `empty-sentences` | partition_reconstruction | partial source derived model | [empty-sentences](#empty-sentences) |
| `diagnostic-cost` | metric_boundary | partial source derived model | [diagnostic-cost](#diagnostic-cost) |

## Model text


### descriptant

#### roundtrip-layer-residuals: wave32

Real joins are pipeline -> frames/tree/world/tally, main -> pipeline/report, tests -> synthetic layer APIs. class supplies labels/costs. lib exposes API/path; reporting and path assembly are tagged independent from codec reconstruction. Root owns volume/mixed sibling joins.

This source-bound partial group organizes existing Mova code. Native evidence and excluded effects are recorded in source sidecars and the root wave32 report. Registration is not a universal proof or whole-system runtime claim.

### model

## roundtrip-layer-residuals

### forward

pipeline composes world decode_exact -> Realizer.sentence -> frames.apply -> tree.decode_exact -> vol.decode_blocks. Frame scripts transport realized origins into parsed heads; world residuals restore global frames and local sentence links. report consumes Tally; CLI selects groups/options and merges per-volume tallies.

### invariant

Exact diagnostic reconstruction requires matching decoder flags/state and all residuals; normal decode and report scores are separate observations. No persistent knowledge or semantic equivalence is implied.

### cost

Sum actual layer costs: greedy frame alignment O(parsed*realized*lemma bytes), world sentence grouping potentially quadratic in frames and quote membership, local-tree sorting sum degree log degree, report cell sorting; annotation/model/I/O costs explicitly unmeasured. World decode_exact also costs O(S*Z+S) time for S requested sentences and Z retained empty-sentence indices, with O(S) output vectors; all-empty input gives quadratic membership comparisons despite zero frames.

### composition

Real joins are pipeline -> frames/tree/world/tally, main -> pipeline/report, tests -> synthetic layer APIs. class supplies labels/costs. lib exposes API/path; reporting and path assembly are tagged independent from codec reconstruction. Root owns volume/mixed sibling joins.

### domain

Small synthetic valid rooted trees, finite frames with sentence-local valid links and bounded allocations; nonoverflowing indices/counters, stable empty override environment.

### limitations

No Annotator/model loading, live corpus, teacher, GPU or complete CLI pipeline execution. Final trailing token spacing false for R2 reconstruction. Invalid arbitrary scripts/graphs are outside exact law.

### checks

- class::wave32::precedence_and_bits
- pipeline::wave32::grouping_drop_and_damage
- report::wave32::zero_normalization_and_rows
- tests::orders_and_projectivity
- tests::tree_script_gives_the_tree_back_and_a_damaged_one_does_not
- tests::world_gives_the_frames_back_and_a_damaged_residual_does_not
- tests::realizer_does_not_repeat_a_shared_subject
- tests::realizer_says_the_content_the_frames_keep
- tests::realizer_says_the_function_words_the_frames_keep
- tests::realizer_hangs_clauses_where_the_links_say
- tests::realizer_punctuates_by_clause_structure
- tests::tam_is_read_and_realized
- tests::pronouns_by_salience
- tests::the_tam_verb_group_keeps_the_frames_content
- tests::verbless_roots_are_fragments
- tests::the_rest_of_a_clause_and_a_phrase_is_kept
- cargo test --offline --locked -p roundtrip --bin roundtrip wave32::spec_failure_order_and_classes -- --exact --test-threads=1

### catalog

### behavior-complement

Exact_ok cannot follow an earlier retained representation mismatch; normal mode cannot recover omitted residual fields by assertion. No persistence/learning effects are performed by pure residual helpers.

### reverse-reconstruction

Encoder-produced residuals with stable state give compatible original sentence/tree/frame witnesses; tally and normal text admit many antecedents.

### head-coordinate-transport

R3 maps zero-based realized origins to one-based parsed heads; R4 maps local frame links to global indices then kept-event coordinates and back.

### decoder-state

Realizer seen ids and off flags must match encode/decode passes; same output alone does not recover state.

### empty-sentences

R4 empties plus XOR starts and nsents restore the original partition, while pipeline Unit changes reset groups.

### diagnostic-cost

Diagnostic bits and equal-set averages are not actual compressed byte lengths or semantic-quality percentages.