Create an ERD based on the Crow's Foot notation using the following requirements:

1. An INVOICE is written by a SALESREP. Each sales representative can write many invoices, but each invoice is written by a single sales representative.
2. The INVOICE is written for a single CUSTOMER. However, each customer can have many invoices.
3. An INVOICE can include many detail lines (LINE), each of which describes one product bought by the customer.
4. The product information is stored in a PRODUCT entity. The product's vendor information is found in a VENDOR entity.