This is my proposal for a “complete” internal system based on Tai Chi’s 5 steps (elements) theory of the thirteen postures:
Earth: Taijiquan
Water: Baguazhang
Wood: Xingyiquan
Metal: Xinyiliuhequan
Fire: Tongbeiquan
All of these systems also have at least some of the applications derived from the other part of the 13 postures-the 8 gates (trigrams) theory. If one wanted to be thorough, they could practice each of the trigram applications 5 different ways according to the style or structure they were trying to emulate; that would be 40 different techniques. However, the 8 gates are only a bit less general than the 5 steps, in that there could be many ways to perform them even with the same structure, so it might be better not to limit one’s practice too much. It would be interesting to explore how the structure taken would effect each of the trigram techniques.
This is only an outline; the book will come later.