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

The groupant beside world/src/induce_gpu.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/induce_gpu.rs`](https://github.com/ElamurAI/mova-free/blob/main/world/src/induce_gpu.rs)
- **source SHA-256:** `3c014cfba45cc70d…`
- **covers:** w=blockIdx*blockDim+threadIdx; w>=nwords returns. Iterate i<j<k in off word range; probe(ci),probe(ci|cj<<21),probe(ci|cj<<21|ck<<42). Match key+rel+1 then atomicAdd1 and return. (bytes 545–2160)
- **part of:** [world-induce-gpu](https://md.groupants.elamur.ai/free/en/mova/world/src/induce_gpu.rs.groupant/)
- **repository folder:** [`world/src/induce_gpu.rs.groupant/subset-kernel.groupant`](https://github.com/ElamurAI/mova-free/tree/main/world/src/induce_gpu.rs.groupant/subset-kernel.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** | unexecuted gpu boundary | [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_induce_gpu_subset_kernel_invariants` | world_induce_gpu_subset_kernel_invariants | partial source derived model | [world_induce_gpu_subset_kernel_invariants](#world-induce-gpu-subset-kernel-invariants) |
| `world_induce_gpu_subset_kernel_resource_cost` | world_induce_gpu_subset_kernel_resource_cost | partial source derived model | [world_induce_gpu_subset_kernel_resource_cost](#world-induce-gpu-subset-kernel-resource-cost) |
| `world_induce_gpu_subset_kernel_representation_join` | world_induce_gpu_subset_kernel_representation_join | partial source derived model | [world_induce_gpu_subset_kernel_representation_join](#world-induce-gpu-subset-kernel-representation-join) |
| `world_induce_gpu_subset_kernel_domain_partition` | world_induce_gpu_subset_kernel_domain_partition | partial source derived model | [world_induce_gpu_subset_kernel_domain_partition](#world-induce-gpu-subset-kernel-domain-partition) |

## Model text


### descriptant

#### world-induce-gpu-subset-kernel

w=blockIdx*blockDim+threadIdx; w>=nwords returns. Iterate i<j<k in off word range; probe(ci),probe(ci|cj<<21),probe(ci|cj<<21|ck<<42). Match key+rel+1 then atomicAdd1 and return.

##### 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. GPU source/embedded CUDA modeled, no native compile, execution or compiled negative control. No surrogate/equivalence measurement.

### approximant

#### Forward relation

w=blockIdx*blockDim+threadIdx; w>=nwords returns. Iterate i<j<k in off word range; probe(ci),probe(ci|cj<<21),probe(ci|cj<<21|ck<<42). Match key+rel+1 then atomicAdd1 and return.

Domain: Well-formed host arrays, reachable sentinel; static-only evidence.

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

No off/cnt bounds checks;21bit atom slots differ from flat offsets. Counts exact only below wrap threshold and trusted valid host table.

Cost component: [cost.md](https://md.groupants.elamur.ai/free/en/mova/world/src/induce_gpu.rs.groupant/subset-kernel.groupant/#cost).

### cost

256threads/block, cubic subsets per word, linear worst probe and serialized contested atomics.

### composition

Host must match hash constants/mask/sentinel; this scoped CUDA string is not executed by lexical Rust AST projection.

### models

### behavior_complement

Out-of-range thread writes nothing. Missing lookup terminates at sentinel; malformed full table may not terminate. Duplicate equal slots route only first match.

### reverse_reconstruction

Observed c[g] admits all input words producing same c[g] queried subsets modulo2^32, no unique recovery of feature grouping or unused values.

### world_induce_gpu_subset_kernel_invariants

No off/cnt bounds checks;21bit atom slots differ from flat offsets. Counts exact only below wrap threshold and trusted valid host table.

### world_induce_gpu_subset_kernel_resource_cost

256threads/block, cubic subsets per word, linear worst probe and serialized contested atomics.

### world_induce_gpu_subset_kernel_representation_join

Host must match hash constants/mask/sentinel; this scoped CUDA string is not executed by lexical Rust AST projection.

### world_induce_gpu_subset_kernel_domain_partition

Well-formed host arrays, reachable sentinel; static-only evidence.

### tests

#### Scoped evidence

Parent selected test names: []. 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/induce_gpu.rs.groupant/#tests). No native GPU compile/execution/control.

Scope bytes [545,2160) are bound to the shared parent syntax projection and full source hash. GPU source/embedded CUDA modeled, no native compile, execution or compiled negative control. No surrogate/equivalence measurement.