>>14152349It makes no sense, since you're using the same basis you can arbitrarily exchange digits (e.g. 1234 + 5678 = 12[7]4 + 56[3]8).
AABA + BBAB = AAAA + BBBB
But AAAA + BBBB = BBBB iff AAAA = 0, but A >= 1.
Also, A and B are really unfortunate variables for base 12, since A = 11 and B = 12.