# 📐 L2 Spec — Elastography (Shear-Wave / Strain) Mismatch-Only Spec
**ID:** `L2-047-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-047`](/artifact/l1/L1-047)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.5 · **Delta tier:** 5
> **⛓ On-chain block:** 41553375
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| H | px | 128 |
| W | px | 128 |
| Snr db | dB | 0.0 – 35.0 |
| Pre load | — | 0.0 – 0.3 |
| F push hz | Hz | 30 – 500 |
| N time samples | — | 50 – 1000 |
| Wave reflections | — | 0.0 – 0.5 |
| Tissue anisotropy | — | 0.0 – 0.3 |
| Boundary conditions | — | 0.0 – 0.3 |
## 2. Tolerance (ε)
**Type:** `fn`
```
12.0 + 0.3 * SNR_dB - 10.0 * wave_reflections - 6.0 * tissue_anisotropy - 6.0 * boundary_conditions
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.5 |
| Delta tier | 5 |
## 4. Fingerprint
`64bb9bff3c9371a6b95a93485ddfd729d8ec773544b6387ea2691329ddc555bb`
## 5. On-chain Registration
- **Chain hash:** `0x7750738d0d5b3b15432747cb19825b1ec76e04944085e44735403aac944cf206`
- **Chain tx hash:** `0x09284461b10d1b1344923c615fa41b581c94ce10510ae405733cd344f1f6c086`
- **Chain block:** `41553375`
---
## File Mapping
This bundle consists of: `L2-047-001.md`, `L2-047-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-047-001.md` | Source of truth — edit this | Human or LLM |
| `L2-047-001.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 `L2-047-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._