Take the following as truth: The gigantic 12th-century Abbatiale Saint-Pierre-et-Saint-Paul was the largest church in Christendom until the completion of Saint Peter's in Rome in the 17th century.
Then the following statement: "Abbatiale Saint-Pierre-et-Saint-Paul was the biggest church in the Christian world from the 12th century until the 17th century." is true, false, or inconclusive?