very interesting thank you so much! For some reason i also use the work "triangulation" but my Sifu talks a bunch about 3 and triangles so...? *shrug* Dont understand but he voice is loud in my head if that makes sense. and it sticks with me.
I use the term "converging" myself. Ji is when two lines converge into one point inside of the opponent. When you use just one hand, like in a punch, the punching arm conveys one line and the other line is implied via the roundness of the body through to the other side of the body, so there are still two lines converging inside the opponent's body, otherwise you'd generate torque and not be in Taiji. Even though PLJA are present in every posture of the form, I personally think that the punch in turn, parry and punch is archetypically Ji. From archetypes you can add whatever kind of powers you want, i.e. you can do An with the punch instead of Ji, but I think the basic level of the straight punch (not really straight) is Ji.
