Na Yin Wood of the Great Forest (大林木): the image of a pillar pair
Na Yin: Wood of the Great Forest (大林木)
Na Yin assigns a poetic image to each consecutive pair of stem-branch combinations. "Wood of the Great Forest" (Da Lin Mu) belongs to the pairs 戊辰 and 己巳.
How Na Yin is used
Traditional readers use Na Yin as a texture layer — an image for the quality of a pillar pair — rather than as a prediction. Different schools weight it differently.
Where you can see it
Build a chart on MingLens to see the Na Yin of your year pillar and check whether "Wood of the Great Forest" appears in your structure.
Boundary
Na Yin images are cultural vocabulary, not statements of fact about a person.