# 📐  L2 Spec — Free Energy Perturbation (FEP + TI + BAR) Mismatch-Only Spec

**ID:** `L2-308-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-308`](/artifact/l1/L1-308)

> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.45 · **Delta tier:** 5
> **⛓ On-chain block:** 41554118

---

## 1. Domain Ω

**Type:** `range`

| Parameter | Unit | Range |
|---|---|---|
| T k | — | 200 – 400 |
| N lambdas | — | 5 – 200 |
| Softcore alpha | — | 0.1 – 1.0 |
| N steps per lambda | — | 10000 – 1000000000.0 |

## 2. Tolerance (ε)

**Type:** `fn`

```
0.5 * (1 + 0.1 * mismatch_severity)
```

## 3. Difficulty

| Property | Value |
|---|---|
| Difficulty score | 0.45 |
| Delta tier | 5 |

## 4. Fingerprint

`e70f8140b861557466a559777bea9b54d71b6812027ad02dd46a4919033dac42`

## 5. On-chain Registration

- **Chain hash:** `0x048935dd9102f1177d210aa1c565e414c838dacc747862dca2c0a27a7025ce0d`
- **Chain tx hash:** `0xd4c87de83871bb3e47ffffd6e25c466b0ddc4f5ebd4eff217dc970ac63f4db54`
- **Chain block:** `41554118`

---

## File Mapping

This bundle consists of: `L2-308-001.md`, `L2-308-001.json`.

| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-308-001.md` | Source of truth — edit this | Human or LLM |
| `L2-308-001.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 `L2-308-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._