# 📐 L2 Spec — XFEM — extended finite element for cracks Mismatch-Only Spec
**ID:** `L2-222-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-222`](/artifact/l1/L1-222)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.48 · **Delta tier:** 5
> **⛓ On-chain block:** 41554015
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| N dof | — | 1000 – 10000000 |
| Snr db | dB | 0 – 40 |
| N enrich | — | 1 – 10000 |
| Level set error | — | 0.0 – 0.1 |
| Enrichment error | — | 0.0 – 0.2 |
| Quadrature error | — | 0.0 – 0.1 |
## 2. Tolerance (ε)
**Type:** `fn`
```
17.0 + 0.3*SNR_dB - 20.0*level_set_error - 10.0*enrichment_error - 20.0*quadrature_error
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.48 |
| Delta tier | 5 |
## 4. Fingerprint
`74327bd5848aff6313a09be149cc1bf25358c773b1e7ae16915d039634c7f3d5`
## 5. On-chain Registration
- **Chain hash:** `0x98c79c6167b8c5aa6876778ba374a324573752762767f6312dd2fea782f0d088`
- **Chain tx hash:** `0xa2cfef35fb0bd5a3166da5c2467a9f79b1f97e139d4954f1b93818a8ede6ecb3`
- **Chain block:** `41554015`
---
## File Mapping
This bundle consists of: `L2-222-001.md`, `L2-222-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-222-001.md` | Source of truth — edit this | Human or LLM |
| `L2-222-001.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 `L2-222-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._