What are six hexagrams, four pillars, magic numbers, strange doors and mysterious spaces, and what are their relations?

Six hexagrams: There are six hexagrams in the Book of Changes. Putting hexagrams in the armor behind An Shiying for divination is called the Six Armor Sutra, also known as the armor divination method. Six-hexagram divination is the ancestor of divination, which is a large-scale divination method.

Four pillars: it is the usual "eight characters". Based on the date of birth, according to the calendar of the Yellow Emperor, the year, month and daily use are represented by one branch. There are four groups of branches, eight characters, so it is called four pillars.

Operation number: it is the general name of all divination. In the past, fortune-telling was also called "arithmetic" and "mathematics", so it was called divination of various arithmetic figures.

Qimen: The full name is Daoism. It is an advanced skill to integrate the good and bad characteristics of time, space and people and study their relationship to avoid misfortune.

Kong Xuan: "Xuan" refers to the cycle (rotation) of the sky, which is equivalent to the concept of time. "Empty" refers to the arrangement of stars in the sky, which is equivalent to the concept of space. It is a kind of knowledge to study the influence of the displacement of stars in the sky over time on specific people and things on the ground. It does not necessarily refer to specific tricks, but is mainly used in specific feng shui schools.

The relationship between them is that all these methods are based on the principles revealed in the Book of Changes.

Most people don't understand. If you want to learn, you must find a master to take you there. But they generally don't accept it.