premise: The Gayer-Anderson Museum beside the Ibn Tulun mosque was built as a private residence in 1540 and amalgamated with a neighboring house called the house of the Cretan Woman (Bayt al-Kritliya) dating from 1631.
hypothesis: In 1540, beside the Ibn Tulun mosque, the Gayer-Anderson Museum was built as a private residence, and amalgamated with a neighboring house called the house of the Cretan Woman.