# Step 0: formula-block-detection

## Read First
- /AGENTS.md
- /PLAN.md
- /PROGRESS.md
- /docs/HARNESS.md
- /docs/IMPLEMENTATION_PLAN.md
- /docs/CONVERSION_POLICY.md
- /phases/2-marker-adapter/step2.md

## Task
Implement formula candidate detection from normalized Marker blocks.

Detect Marker equation blocks and text-pattern candidates while classifying inline versus block formulas based on block role and layout hints.

## Sprint Contract
- Done means: formula candidates are represented as internal objects ready for Nougat or Marker fallback.
- Hard thresholds: ordinary currency-like dollar text is not blindly treated as math; inline/block distinction is tested; no Nougat invocation occurs yet.
- Files owned: `src/pdftomd/formulas.py`, tests, `PROGRESS.md`, `phases/3-formula-pipeline/index.json`.
- Dependencies: Phase 2 block normalization.

## Acceptance Criteria
```powershell
python scripts\validate_workspace.py
.\venv\python.exe -m pytest tests
```

## Verification
1. Run the acceptance commands.
2. Confirm tests include inline and block formula candidates.
3. Update `PROGRESS.md` and this phase index.

## Do Not
- Do not call Nougat.
- Do not render Markdown math.
- Do not make regex the only source when structured block role exists.