Fictional original teaching data. All names and invoice IDs invented. Currency CNY. Reference date 2026-10-24.
Email E01, message-id msg-a: invoice INV-100 from 松风材料社, buyer 青禾工作室. Issue 2026-10-20. Subtotal 100.00, tax 0.00, total 100.00. Attachment hash demo-a.
Email E02, message-id msg-a-forward: exact forwarded copy of INV-100, same supplier, issue date, amounts, attachment hash demo-a. Do not insert twice.
Email E03, message-id msg-b: invoice INV-101 from 松风材料社, buyer 青禾工作室. Issue 2026-10-21. Subtotal 80.00, tax field absent, total 80.00. Attachment hash demo-b. Absent tax is null, not zero.
Email E04, message-id msg-c: invoice INV-102 from 北门纸品社, buyer 青禾工作室. Issue 2026-10-22. Line items 2 x 30.00 = 60.00, tax 6.00, printed total 68.00. Attachment hash demo-c. Printed total conflicts with 66.00 sum; hold for human review.