The image shows two datatypes, Invoice and P.O. The line item datatype members of Invoice are mapped to the item datatype members of P.O. The datatype members of line item, which are id, qty, cost, and desc are respectively mapped within an invoked mapping to the datatype members of item, which are identifier, quantity, cost, and description. The lang datatype member of desc is mapped to the lang datatype member of description. End of description.