# 📐 L2 Spec — Adaptive Filtering Non-Stationary Spec (echo cancellation family)
**ID:** `L2-395-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-395`](/artifact/l1/L1-395)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.55 · **Delta tier:** 5
> **⛓ On-chain block:** 41555202
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| L | — | 4 – 4096 |
| Mu | — | 1e-05 – 1.0 |
| Sigma v | — | 0.0001 – 1.0 |
| Eigenspread | — | 1 – 1000 |
| Step size miscal | — | 0.0 – 5.0 |
| Non stationarity rate | — | 0.0 – 0.1 |
| Impulsive noise fraction | — | 0.0 – 0.1 |
## 2. Tolerance (ε)
**Type:** `fn`
```
-30 + 10 * log10(eigenspread / 10) + 20 * log10(non_stationarity_rate / 0.01 + 1) + step_size_miscal * 3
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.55 |
| Delta tier | 5 |
## 4. Fingerprint
`7b6344ddc34326eae5b7bd4efc0b5d9d8c989ee3b7ae20c784ab5681228289bf`
## 5. On-chain Registration
- **Chain hash:** `0x8f1d5bc96fe601c11fe2b47b7157de06558bd826fa8190f7bd14327c7dd9b8da`
- **Chain tx hash:** `0x61f7fa66108852e179fe9d11a7aeeeb1cda7d528d516f435647a50b1ce4c7647`
- **Chain block:** `41555202`
---
## File Mapping
This bundle consists of: `L2-395-001.md`, `L2-395-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-395-001.md` | Source of truth — edit this | Human or LLM |
| `L2-395-001.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 `L2-395-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._