# 📐 L2 Spec — MR Angiography (time-of-flight / phase-contrast) Mismatch-Only Spec
**ID:** `L2-058-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-058`](/artifact/l1/L1-058)
> **🎯 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 | — | 32 – 512 |
| Te ms | ms | 3 – 30 |
| Tr ms | ms | 10 – 100 |
| Snr db | dB | 0.0 – 35.0 |
| Motion | — | 0.0 – 0.5 |
| Pulsatility | — | 0.0 – 0.3 |
| Inplane saturation | — | 0.0 – 0.5 |
| Turbulence dephasing | — | 0.0 – 0.3 |
## 2. Tolerance (ε)
**Type:** `fn`
```
14.0 + 0.3 * SNR_dB - 10.0 * inplane_saturation - 8.0 * motion - 5.0 * turbulence_dephasing
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.5 |
| Delta tier | 5 |
## 4. Fingerprint
`d0a0edb6fef723979b0952933f391c50c810722448ca95e99811d0cc051eeba8`
## 5. On-chain Registration
- **Chain hash:** `0x151a21dbcd967a6296cc5240e78e1a87a2efbd08eaa4056fbfc4738d23a1362e`
- **Chain tx hash:** `0xdae3bdc999f1e7e919e6190eb64ee1370abb914fd2379780fc27d5c43809f16c`
- **Chain block:** `41553361`
---
## File Mapping
This bundle consists of: `L2-058-001.md`, `L2-058-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-058-001.md` | Source of truth — edit this | Human or LLM |
| `L2-058-001.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 `L2-058-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._