# 📐  L2 Spec — Physiologically Based PK (PBPK) — Nominal + Mismatch Specs

**ID:** `L2-403-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-403`](/artifact/l1/L1-403)

> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.38 · **Delta tier:** 5
> **⛓ On-chain block:** 41555221

---

## 1. Domain Ω

**Type:** `range`

| Parameter | Unit | Range |
|---|---|---|
| Cl int l hr | — | 0.1 – 1000 |
| Species bw kg | kg | 0.02 – 500 |
| N organs modeled | — | 5 – 25 |
| Fu fraction unbound | — | 0.001 – 1.0 |

## 2. Tolerance (ε)

**Type:** `fn`

```
1.5 + 0.5 * (0.1 / fu_fraction_unbound) ** 0.2
```

## 3. Difficulty

| Property | Value |
|---|---|
| Difficulty score | 0.38 |
| Delta tier | 5 |

## 4. Fingerprint

`724ebec7228c81f78128c7e244cd500d56dbfb025b948df8ebe59f75e2bcede6`

## 5. On-chain Registration

- **Chain hash:** `0x545c116ef1cf4e00449e10bf725ebad61ffe9516018e11c3c37f6f5bf5878582`
- **Chain tx hash:** `0x0155d7c0d1a5479bf286a3cc31ee11090fef76c79ab9d199803b4eaf93abac52`
- **Chain block:** `41555221`

---

## File Mapping

This bundle consists of: `L2-403-001.md`, `L2-403-001.json`.

| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-403-001.md` | Source of truth — edit this | Human or LLM |
| `L2-403-001.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 `L2-403-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._