Two possible HouTian sequences，
and,
represent the uncertainty created when the repeating sequence,
震 离艮坤 乾兑坎 巽 乾兑坎 离艮坤
is reduced to four unique states,
forming the BaGua again from this four, requires the addition of one Yao, which can be Ying or Yang. This ambiguity translates into two possible sequences. Which leads to two possible 64 hexagram sequences.
If we allow for the fact that at the next instance, the TianGua might remain unchanged, we have
2(HouTian sequences) X 2(change/unchanged HouTian Gua) X 2(change/unchanged XianTian Gua)
equals eight possibilities (or eight possible hexagrams), which is the number of Gua, we started with.
It seems that we are back to representing all changes with BaGua.
Good night...
