# 📐 L2 Spec — Hall MHD — ion-scale physics in reconnection Mismatch-Only Spec
**ID:** `L2-353-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-353`](/artifact/l1/L1-353)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.48 · **Delta tier:** 5
> **⛓ On-chain block:** 41554100
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| H | px | 32 – 2048 |
| W | px | 32 – 2048 |
| Snr db | dB | 0 – 40 |
| N times | — | 50 – 100000 |
| Hall closure error | — | 0.0 – 0.2 |
| Finite larmor error | — | 0.0 – 0.3 |
| Electron inertia error | — | 0.0 – 0.2 |
## 2. Tolerance (ε)
**Type:** `fn`
```
14.0 + 0.3*SNR_dB - 15.0*hall_closure_error - 15.0*electron_inertia_error - 8.0*finite_larmor_error
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.48 |
| Delta tier | 5 |
## 4. Fingerprint
`7d2049d00578b1522d375179f701c677dfdc50ffdee20d09a4412e6c8e97227b`
## 5. On-chain Registration
- **Chain hash:** `0x768e91e48b5e3b319b725f111c18d854f4f305d8000d72d641dd09f720c217d5`
- **Chain tx hash:** `0xbd3247da37ddcb8c3b9a8fd966963e0e0fca58343daac0870957115c07578b8c`
- **Chain block:** `41554100`
---
## File Mapping
This bundle consists of: `L2-353-001.md`, `L2-353-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-353-001.md` | Source of truth — edit this | Human or LLM |
| `L2-353-001.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 `L2-353-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._