The wikipedia page on Brahma Sutras says there are 555 verses. In the book that I have, Brahma Sutras According to Sri Ramanuja, by Swami Vireswarananda and Swami Adidevananda, published by Advaita Ashrama, it says there are 544 verses. This summary of pancharatra agamas says there are 565.
So my question is, how many Brahma Sutras are there, and do some people consider a different amount because of lost verses?
In his Introduction to his translation of Ramanuja's Sri Bhasya, Swami Vireswarananda writes (p xxviii):
It has already been stated that the Sutra literature, owing to its extreme brevity of thought, is unintelligible. This difficulty becomes greatly enhanced in the absence of an unbroken tradition. While there is an accepted tradition as regards the the division into Chapters (Adhyayas) and Sections (Padas), there is no such tradition as regards the division into topics (Adhikaranas), nor as regards the texts of the Scriptures (Sruti) that are discussed therein. Again, the same Sutra sometimes yields just the opposite meaning by a mere shifting of the stops, e.g., Sankara's and Ramanuja's commentaries on III.ii.11. The total number of Sutras, too, differs in the various commentaries, and sometimes a single Sutra is split into two, or two Sutras are combined into one, or a Sutra is dropped, or a new one added. The readings of the Sutras also differ in the various commentaries and the addition of a single [Sanskrit] letter like (but), (and), or (the negative) makes the meaning completely different. Some of the words, too, used in the Sutras are very ambiguous, for in the Upanishads themselves they convey different meanings in different places. All this gives the commentaries freedom to interpret the Sutras according to their predilections.
