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Original study guide · 18

Hexagram 18 · Gǔ (山风蛊)

Direct summary

Hexagram 18, Gǔ (山风蛊), places Xùn (巽, Wind) below Gèn (艮, Mountain).

Its nuclear form is Hexagram 54; its opposite and reversed forms coincide at Hexagram 17.

Structure reading

The lower trigram is Xùn (巽, Wind); the upper trigram is Gèn (艮, Mountain).

Sequence context

In the received sequence, Hexagram 18 comes between Hexagrams 17 and 19.

Study prompt

Compare Hexagram 18 with its nuclear form (54), then examine why the opposite and reversed transformations both lead to Hexagram 17. What structural feature makes them coincide?

Editorial references

  1. Yi structural index: King Wen number, name, trigrams, and nuclear, opposite, and reversed forms.
  2. Yi editorial method: site-authored guidance is kept separate from classical text.
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Yi original study guidance based on verified structural facts. No restricted source passage is reproduced.