SEO Article Introduction Generator — illustrative example

INPUT
Write an introduction for a guide to comparing an invoice with a purchase order. Cover supplier, reference, quantity and unit price; discrepancies need review.

RESULT
Start an invoice-to-purchase-order check by matching the supplier and order reference. Then compare each line's quantity and unit price. This guide shows how to separate price differences from quantity differences and record the exceptions for review before payment approval.

REVIEW
An introduction should orient the reader and begin answering the query promptly. Avoid a long generic preamble before the useful part.

This is a teaching example, not a live execution record.