# 📐 L2 Spec — Diffusion MRI (DWI / DTI / HARDI) Mismatch-Only Spec
**ID:** `L2-045-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-045`](/artifact/l1/L1-045)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.5 · **Delta tier:** 5
> **⛓ On-chain block:** 41552979
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| H | px | 64 |
| W | px | 64 |
| Z | — | 16 – 256 |
| Snr db | dB | 0.0 – 35.0 |
| Motion | — | 0.0 – 0.5 |
| N directions | — | 6 – 256 |
| B0 distortion | — | 0.0 – 0.3 |
| Eddy currents | — | 0.0 – 0.3 |
| B max s per mm2 | — | 100 – 5000 |
| Partial volume csf | — | 0.0 – 0.3 |
## 2. Tolerance (ε)
**Type:** `fn`
```
12.0 + 0.3 * SNR_dB + 2.0 * log2(N_directions / 6) - 8.0 * eddy_currents - 6.0 * motion - 6.0 * B0_distortion
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.5 |
| Delta tier | 5 |
## 4. Fingerprint
`6d2c50a5432dad763e7b113f8b41a84f36d22f1736dc8017b95b05024cae25cc`
## 5. On-chain Registration
- **Chain hash:** `0x9ec3c82f3b76ef25cd0c716af5cd07827b92d6899acbf6bcca0cdeec4ae70535`
- **Chain tx hash:** `0xe6ce3d5e1d2c49b80439f596511fe4e1dfdbf2f07e969e79a2cd6d8d359b4cd1`
- **Chain block:** `41552979`
---
## File Mapping
This bundle consists of: `L2-045-001.md`, `L2-045-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-045-001.md` | Source of truth — edit this | Human or LLM |
| `L2-045-001.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 `L2-045-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._