While reading biography of Ramanujacharya, I came to find that Baudhayana, who is known as Vrittikara, wrote a commentary on Vedavyasa's Brahma Sutra. In the time of Ramanujacharya, this work of Bodhayana is not easily available. He tried to get the copy of Bodhayana Vritti in whole country and finally he found that it's only available and preserved in the library at Kashmir. Ramanujacharya wrote Bhashya on Vedanta Sutra on the basis of (or taking the reference from) Bodhayana Vritti as described in the biography of Ramanujacharya.
Now I think that if it's very difficult to get Bodhayana Vritti in time of Ramanujacharya then it would be quite possible that it would be easily available in the time of Adi Shankaracharya. So, he might be aware about this work of Bodhayana and possibly he had quoted in his Bhashya on Brahma Sutra.
So, I want to know whether Adi Shankaracharya has quoted Bodhayana Vritti in his Bhashya on Brahma Sutra? If yes, then I would more like to know whether he quoted as Purvapaksha (in disagreement) or as Siddhanti (in agreement)?