If we proceed to form the BaGua again from this new SiXiang series,
we have,
离 震 艮 坤 乾 兑 巽 坎
which is none of the established sequences, 后天 nor 先天. The binary sequence,
is here the XianTian (先天) sequence. The previous sequence is HouTian (后天) sequence.
If this is the case then, we have a totally different 64 hexagram sequence when we place 后天 below 先天 to form a hexagram.This adds a new dimension, where one hexagram to the next is a 'timed' progression. There will actually be a next instance in time in this series of hexagrams. The Gua below due to the 后天 series may or may not progress to the next with every regular step in the 先天, top Gua. There is only one uncertainty; does the bottom Gua change to the next Gua in the HouTian (后天) series? A fifty-fifty percent chance, that can be captured by one Yao (爻).
One toss of a coin. Head or tail?
Note: If Ying Yao is placed first as the trigram is formed from SiXiang, we have the series
震 离 坤 艮 兑 乾 坎 巽 instead.
This is still not the two XianTian (先天) and HouTian (后天) sequences in common literature.
乾 兑 离 震 巽 坎 艮 坤 (伏羲八卦次序) nor,
乾 坎 艮 震 巽 离 坤 兑 (文王八卦次序).
