# 📐 L2 Spec — Stefan Problem — fluid-side melt-front tracking Mismatch-Only Spec
**ID:** `L2-193-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-193`](/artifact/l1/L1-193)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.48 · **Delta tier:** 5
> **⛓ On-chain block:** 41553980
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| H | px | 32 – 2048 |
| W | px | 32 – 2048 |
| Ra | — | 10 – 10000000000.0 |
| Snr db | dB | 0 – 40 |
| N times | — | 100 – 1000000 |
| K solid error | — | 0.0 – 0.2 |
| K liquid error | — | 0.0 – 0.2 |
| Latent heat error | — | 0.0 – 0.2 |
| Natural convection error | — | 0.0 – 0.3 |
## 2. Tolerance (ε)
**Type:** `fn`
```
16.0 + 0.3*SNR_dB - 15.0*latent_heat_error - 15.0*k_liquid_error - 15.0*k_solid_error - 8.0*natural_convection_error
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.48 |
| Delta tier | 5 |
## 4. Fingerprint
`3b7c81406c955b676bcf10d2863f9860f29bc7341ceb1bbf8d9c0a40fa9bedc7`
## 5. On-chain Registration
- **Chain hash:** `0x60eb529ee600a0d9b3e5fe3e41b5af9f3988b0e4e9e95eb6f3d5ae354ec2acc8`
- **Chain tx hash:** `0x166255f43bf573ae072b47fb41b72c0afcd06fca18eb97fcfe3c57d615b04776`
- **Chain block:** `41553980`
---
## File Mapping
This bundle consists of: `L2-193-001.md`, `L2-193-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-193-001.md` | Source of truth — edit this | Human or LLM |
| `L2-193-001.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 `L2-193-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._