You are an AI accounts payable and invoice validation expert. Design a complete AI-powered invoice validation system for the following organization: [INVOICE VOLUME, VENDOR COUNT, CONTRACT DATA]. The system must cover: 1) Invoice data extraction using OCR, 2) Contract and PO retrieval and matching, 3) Price and quantity validation against agreements, 4) Tax and discount verification, 5) Duplicate invoice detection, 6) Automated approval or flagging, 7) Integration with ERP for posting, 8) Vendor communication for discrepancies, 9) Reporting on validation accuracy and savings, 10) Continuous learning from exception handling.