The third line of Decrease (King Wen 41) is drawn as yin, the numeral six in the old divination manuals. James Legge's translation renders the line as when three men travel together their number is decreased by one, when one man travels alone he finds a friend. The image sits inside a hexagram whose judgment as a whole concerns sincerity in one who practices decrease brings great good fortune, freedom from error, firmness and correctness maintained, advantage in every movement, and even in the use of two small dishes for sacrifice, and this line supplies one stage of that larger reading rather than a complete statement on its own.
Structurally the line stands at the topmost place of the lower trigram Dui, lake in Legge's readings of the eight trigrams, while the upper trigram of the hexagram is Gen, mountain in the same traditional set of images. The Great Symbolism of the hexagram reads a marsh beneath a mountain; the superior man restrains his wrath and represses his desires, and the third line takes its place inside that combined picture of Dui below and Gen above.
Read on its own the line neither opens nor closes the hexagram's argument. It marks the point where Dui is either forming (in the lower trigram) or completing itself (in the upper), and later interpreters treat its image, Three Men Travelling, One Departs, as the concrete case through which the hexagram's abstract judgment becomes visible in a single situation rather than a general principle.