# 📐 L2 Spec — CASSI Mismatch-Only Spec (KAIST benchmark family)
**ID:** `L2-025-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-025`](/artifact/l1/L1-025)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.45 · **Delta tier:** 5
> **⛓ On-chain block:** 41554172
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| H | px | 64 – 2048 |
| W | px | 64 – 2048 |
| N bands | bands | 8 – 128 |
| Mask dx | — | 0.0 – 1.0 |
| Mask dy | — | 0.0 – 1.0 |
| Mask theta | — | 0.0 – 0.15 |
| Noise level | — | 0.001 – 0.1 |
| Mask density | — | 0.3 – 0.7 |
| Disp a1 error | — | 0.0 – 0.05 |
| Disp alpha error | — | 0.0 – 0.3 |
## 2. Tolerance (ε)
**Type:** `fn`
```
25.0 + 2.0 * log2(H / 64) + 1.5 * log10(photon_count / 50)
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.45 |
| Delta tier | 5 |
## 4. Fingerprint
`641beec700ce78fb5cf4061eb9f20727f2e7785c21f0c70d687daec0f4d0bfb3`
## 5. On-chain Registration
- **Chain hash:** `0xe08488dd8e1abbfd3e20c846ad2a40254b0651b0a51f3941f7a37c3fec302409`
- **Chain tx hash:** `0x6590f4cd51cc7b716d0f2b6ae004afb726ecdc8cfbf5ce26f00447856a694143`
- **Chain block:** `41554172`
---
## File Mapping
This bundle consists of: `L2-025-001.md`, `L2-025-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-025-001.md` | Source of truth — edit this | Human or LLM |
| `L2-025-001.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 `L2-025-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._