# 📐 L2 Spec — CDI Mismatch-Only Spec (shrinkwrap-assisted single-pattern recovery)
**ID:** `L2-072-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-072`](/artifact/l1/L1-072)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.55 · **Delta tier:** 5
> **⛓ On-chain block:** 41554173
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| H | px | 128 – 4096 |
| W | px | 128 – 4096 |
| Background | — | 0.0 – 0.05 |
| Photon count | — | 10 – 100000 |
| Partial coherence | — | 0.7 – 1.0 |
| Oversampling sigma | — | 2.0 – 8.0 |
| Support mask error | — | 0.0 – 0.3 |
| Beam stop radius px | — | 0 – 50 |
## 2. Tolerance (ε)
**Type:** `fn`
```
18.0 + 3.0 * log2(oversampling_sigma / 2.0) + 2.0 * log10(photon_count / 10) - 10.0 * support_mask_error
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.55 |
| Delta tier | 5 |
## 4. Fingerprint
`450ef760230bacaf259391c21e2cbcac34289ec5b7f11f82ed924b3c40576dce`
## 5. On-chain Registration
- **Chain hash:** `0x7654aecb73fd6a10ac2a8314e5e4b76ef9000f152640652cb43e3ba8dbf77b94`
- **Chain tx hash:** `0x838ba0c42b14b6841430651b17a6ddbf00ccc1c5b1ebfc2897c60e37983be0af`
- **Chain block:** `41554173`
---
## File Mapping
This bundle consists of: `L2-072-001.md`, `L2-072-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-072-001.md` | Source of truth — edit this | Human or LLM |
| `L2-072-001.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 `L2-072-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._