# 📐 L2 Spec — Dual-Energy X-ray Absorptiometry (DEXA) Mismatch-Only Spec
**ID:** `L2-037-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-037`](/artifact/l1/L1-037)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.5 · **Delta tier:** 5
> **⛓ On-chain block:** 41552606
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| H | px | 512 |
| W | px | 256 |
| Mas | — | 1 – 100 |
| Kvp hi | — | 100 – 150 |
| Kvp lo | — | 60 – 80 |
| Pixel mm | mm | 0.1 – 2.0 |
| Beam hardening | — | 0.0 – 0.2 |
| Calibration drift | — | 0.0 – 0.05 |
| Patient alignment | — | 0.0 – 2.0 |
| Fat fraction variation | — | 0.0 – 0.3 |
## 2. Tolerance (ε)
**Type:** `fn`
```
22.0 + 2.0 * log10(mAs / 1) - 15.0 * beam_hardening - 2.0 * patient_alignment
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.5 |
| Delta tier | 5 |
## 4. Fingerprint
`c0ade40189f4a55d3db90424257499b0d8a62e803a61da8f901b08ce572e141c`
## 5. On-chain Registration
- **Chain hash:** `0xee566b3c281fc49b05f04af22c25e22b72893f0abf030ffc839903a39a804faa`
- **Chain tx hash:** `0xf993863305ec16dfb15988f81df7a8c9de1363598914dc1914ce9c62d2c1917f`
- **Chain block:** `41552606`
---
## File Mapping
This bundle consists of: `L2-037-001.md`, `L2-037-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-037-001.md` | Source of truth — edit this | Human or LLM |
| `L2-037-001.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 `L2-037-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._