PDFToMD/phases/3-formula-pipeline/step0.md

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

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.