# 📐 L2 Spec — Digital Breast Tomosynthesis (DBT) Mismatch-Only Spec
**ID:** `L2-063-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-063`](/artifact/l1/L1-063)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.5 · **Delta tier:** 5
> **⛓ On-chain block:** 41553375
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| H | px | 1664 |
| W | px | 1280 |
| Z | — | 16 – 200 |
| Kvp | — | 22 – 34 |
| Mas | — | 10 – 400 |
| Scatter | — | 0.0 – 0.3 |
| Pixel um | µm | 50 – 200 |
| N projections | — | 9 – 25 |
| Patient motion | — | 0.0 – 0.3 |
| Tilt range deg | deg | 7.5 – 30 |
| Compression variation | — | 0.0 – 0.2 |
| Limited angle artifacts | — | 0.1 – 0.7 |
## 2. Tolerance (ε)
**Type:** `fn`
```
19.0 + 2.0 * log10(mAs / 10) + 1.0 * log2(tilt_range_deg / 7.5) - 10.0 * limited_angle_artifacts - 8.0 * scatter
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.5 |
| Delta tier | 5 |
## 4. Fingerprint
`6b7a539bb3627da67330ccfaf4181737f72bacbe942d605d17be290e589cbe96`
## 5. On-chain Registration
- **Chain hash:** `0xc83f35ee2e2490244b2cceed4dcd92cfb6985ad7a26a48a5cdfe7759e38e9e1d`
- **Chain tx hash:** `0x45024ebeddd12500094e807b9c648fd87a324267156c7991524a04fdd4f55d85`
- **Chain block:** `41553375`
---
## File Mapping
This bundle consists of: `L2-063-001.md`, `L2-063-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-063-001.md` | Source of truth — edit this | Human or LLM |
| `L2-063-001.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 `L2-063-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._