# 📐 L2 Spec — Pneumothorax Detection from Chest X-ray (PWDR) — Spec Skeleton
**ID:** `L2-523-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-523`](/artifact/l1/L1-523)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.5 · **Delta tier:** 5
> **⛓ On-chain block:** 41552981
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| H | px | 1024 – 4096 |
| W | px | 1024 – 4096 |
| Kvp | — | 70 – 130 |
| Mas | — | [NEEDS_HAND_AUTHORING: bounds] |
| Snr db | dB | [NEEDS_HAND_AUTHORING: bounds] |
| Pa or ap | — | [NEEDS_HAND_AUTHORING: bounds] |
| Rotation artifact | — | [NEEDS_HAND_AUTHORING: bounds] |
| Pixel resolution um | µm | 50 – 300 |
| Bullous disease confounders | — | [NEEDS_HAND_AUTHORING: bounds] |
| Skin fold pseudo pneumothorax | — | [NEEDS_HAND_AUTHORING: bounds] |
| Supine vs upright acquisition | — | [NEEDS_HAND_AUTHORING: bounds] |
| Bilateral severity disagreement | — | [NEEDS_HAND_AUTHORING: bounds] |
| Expiratory vs inspiratory state | — | [NEEDS_HAND_AUTHORING: bounds] |
## 2. Tolerance (ε)
**Type:** `fn`
```
0.85_accuracy
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.5 |
| Delta tier | 5 |
## 4. Fingerprint
`dec24c9802d1021e03b692664c6eb1995f53baf0e130ac1ceab911bbeb3090bc`
## 5. On-chain Registration
- **Chain hash:** `0xa285e702696ba60b9b828347ed987c2eef7d12ee9cb1bb521b821a48999d0a4a`
- **Chain tx hash:** `0x582f4e4c967d4e0b0c1bcfc06eca563e46ee42eae5bc048920e61f7da9bdc84a`
- **Chain block:** `41552981`
---
## File Mapping
This bundle consists of: `L2-523-001.md`, `L2-523-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-523-001.md` | Source of truth — edit this | Human or LLM |
| `L2-523-001.json` | Structured metadata for the registry | LLM regenerates from the sections above |
**Prompt for your LLM after editing this Markdown:**
> Read the attached Markdown. Regenerate the sibling `.json` so every field matches.
> Preserve the schema documented in the rows above.
> Output each file in its own fenced code block tagged with the filename.
> Output only the JSON object.
_This Markdown was auto-synthesized from the catalog row for `L2-523-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._