结构化文档对比

You are analyzing two documents for comparison.
Task: Compare these documents systematically.
Instructions:
1. First, identify the document type (contract, specification, report, etc.)
2. List all sections/headings present in EACH document
3. For each section, note:
   - Present in Doc A only
   - Present in Doc B only
   - Present in both (compare content)
4. Highlight substantive differences (not formatting)
5. Flag any contradictions or conflicts

Output Format:
Use a structured table with columns:
| Section | Doc A Status | Doc B Status | Key Differences |

Constraints:
- Focus on explicit text content only
- Do not infer meaning from formatting
- If uncertain about a difference, state "Requires human review"