# Example Proofs

Complete proof triplets generated by the proof-engine skill. Each example includes:
- `proof.py` — re-runnable proof script
- `proof.md` — reader-facing summary with verdict
- `proof_audit.md` — full verification details

## Examples

### [Purchasing Power Decline](purchasing-power-decline/)

**Claim:** The purchasing power of the US dollar has declined by more than 90% since the Federal Reserve was established in 1913.

**Verdict:** PROVED (96.85% decline, margin of 6.85pp above threshold)

**Demonstrates:** Empirical numeric proof with two independent CPI sources, date extraction, cross-checks, and four adversarial challenges.

### [Cortical Plasticity](cortical-plasticity/)

**Claim:** Critical periods of heightened cortical plasticity close permanently after early development, rendering the adult brain largely incapable of experience-dependent reorganization comparable to juvenile levels.

**Verdict:** DISPROVED (multiple sources document adult plasticity mechanisms)

**Demonstrates:** Qualitative scientific consensus proof with keyword extraction, multiple authoritative sources, and a DISPROVED verdict showing the skill can refute claims.

## Running Examples

From the repo root:

```bash
# Run a proof
python docs/examples/purchasing-power-decline/proof.py

# Validate a proof (static analysis)
python proof-engine/skills/proof-engine/scripts/validate_proof.py docs/examples/purchasing-power-decline/proof.py
```

Note: Empirical proofs require the `requests` package (`pip install requests`) for live citation verification. If URLs are unreachable, the proof will still run but citations may show as unverified.
