參考the letters, the pairs, the eight stars — all the working, none of the reading

Heavenly Doctor, Vitality, Longevity and Stability are the four lucky stars. Five Ghosts, Six Killings, Mishap and Ending Fate are the four unlucky stars. Readings follow the classical eight-house number system. A lens, not a verdict.

Why these pairs: each digit stands for one of the eight trigrams in the later-heaven arrangement. 1 is 坎 water, 2 坤 earth, 3 震 wood, 4 巽 wood, 6 乾 metal, 7 兌 metal, 8 艮 earth, 9 離 fire. Two digits side by side are two trigrams stacked, which makes one of the sixty-four hexagrams, and each hexagram's classical verdict sorts its pair into one of the eight stars. 5 and 0 sit at the centre and belong to no trigram, so they are never paired: a 5 strengthens the pair beside it, a 0 cancels the pair before it.