# 📐  L2 Spec — 21cm Cosmology Reionization Signal — Nominal + Mismatch Specs

**ID:** `L2-378-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-378`](/artifact/l1/L1-378)

> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.5 · **Delta tier:** 5
> **⛓ On-chain block:** 41555182

---

## 1. Domain Ω

**Type:** `range`

| Parameter | Unit | Range |
|---|---|---|
| Noise k | — | 0.01 – 0.5 |
| N antennas | — | 20 – 1000 |
| Integration hours | — | 100 – 10000 |
| Foreground level k | — | 50 – 1000 |

## 2. Tolerance (ε)

**Type:** `fn`

```
1.5 + 0.5 * sqrt(integration_hours / 1000)
```

## 3. Difficulty

| Property | Value |
|---|---|
| Difficulty score | 0.5 |
| Delta tier | 5 |

## 4. Fingerprint

`f163ee6b8f31ce67c4a800d45f9e34070a56e0d881792fc2a85d59d2138b8b71`

## 5. On-chain Registration

- **Chain hash:** `0xb6d9e6c52bdd0d26f1e64125360087d4f4d0209b2f10cc1d3ddaf1622a1703b8`
- **Chain tx hash:** `0x332428d7af827e50dd61f0af3874b9f76cdd993fae506ba2d3a1512c7f9aaf9e`
- **Chain block:** `41555182`

---

## File Mapping

This bundle consists of: `L2-378-001.md`, `L2-378-001.json`.

| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-378-001.md` | Source of truth — edit this | Human or LLM |
| `L2-378-001.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 `L2-378-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._