Way to visualise intertype relationships: people can be connected in two basic ways: either by direct energy flow from one to the other, or by a lining up of the functions through mutual exchange with some third object. Extraverted and introverted functions are modelled in accordance with their energy flow from or to the environment, and so functions of the same attitude cannot easily directly flow into each other, whereas functions of opposite attitude can. Any energy-object has a rating for its capability of interacting with each of the functions, and some basic arithmetic on these values we can obtain an energy flow rating. This flow will have a "direction", in analogy with the viewpoint at which the "Length" function was arrived at. I think I will study circuit diagrams so I'll be able to model this in a formal science manner. though on second thoughts I'm pretty sure I wouldn't need to