# 📐 L2 Spec — Optical Coherence Tomography (OCT) Mismatch-Only Spec
**ID:** `L2-042-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-042`](/artifact/l1/L1-042)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.5 · **Delta tier:** 5
> **⛓ On-chain block:** 41553361
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| H | px | 128 |
| W | px | 128 |
| Z | — | 256 – 4096 |
| Snr db | dB | 10.0 – 45.0 |
| Pixel um | µm | 1 – 20 |
| Lambda bw nm | nm | 20 – 200 |
| Speckle noise | — | 0.0 – 0.3 |
| Signal roll off | — | 0.0 – 0.3 |
| Lambda center nm | nm | 830 – 1310 |
| Motion artifacts | — | 0.0 – 0.3 |
| Dispersion mismatch | — | 0.0 – 0.3 |
## 2. Tolerance (ε)
**Type:** `fn`
```
20.0 + 0.3 * SNR_dB - 10.0 * dispersion_mismatch - 6.0 * motion_artifacts - 5.0 * speckle_noise
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.5 |
| Delta tier | 5 |
## 4. Fingerprint
`7be5e237b53642ab690e76748193362b4ea700b941817a31a685e0b5454c1910`
## 5. On-chain Registration
- **Chain hash:** `0xbff2cf67a18f218a802b21d16f889a56eb8b3a0fc82b5103ffa74d2c67241307`
- **Chain tx hash:** `0x8602db3fb4fcadf86447d305b6ffc6299d7da9d9d971f09fd036c05814e63e1e`
- **Chain block:** `41553361`
---
## File Mapping
This bundle consists of: `L2-042-001.md`, `L2-042-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-042-001.md` | Source of truth — edit this | Human or LLM |
| `L2-042-001.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 `L2-042-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._