In past few weeks I got really interested in Penetrating/Thrusting/Center/Chong Vessel and Taiji Pole. Some resource say that Chong Mai is in the Taiji Pole, and then others call Taiji Pole Center Vessel which is the name also of Chong Mai. There are lot of information about them but they are not clear about neither of them.   So, is Taiji Pole different name for Thrusting Vessel? What are they? Can you recommend some good resource upon that?   Thanks.