Swami Desikan, in his commentary on Chatushloki, has quoted four chapters from Brahma Sutra in the introductory shloka and says that Perumal and Piratti hold equal status. Have heard the same from a YouTube lecture by Sri Karuppankadu Swamigal. If this is wrong, please provide a proper explanation. Also, please clarify whether Swami Desikan has presented this same in Shrimad Rahasya Traya Saram or other treatises.