Original sentence: A cathedral has a specific ecclesiatical role and administrative purpose.A cathedral is a church, usually Roman Catholic, Anglican, or Eastern Orthodox, housing the seat of a bishop
Edited sentence: A cathedral has a specific ecclesiatical role and administrative purpose as the seat of a bishop.The cathedral architecture of Western Europe is the architecture of a large group of church buildings, occupying a specific ecclesiastical role, and following a tradition of form, function and style that stems initially from Early Christian traditions of the Roman Empire