Field theory of unification in nonlinear and linear network (II)——Theoretical content of field theory

Two forms of basic equations and 5 basic matrices in the matrix analysis of networks from nonlinear networks to linear networks are obtained and their origins in physics are correctly explained. Furthermore, the whole 12 general characteristic formulae of the 4 fundamental network elements as well as some important new results, which were not in the conventional theory, have also been obtained during inference for both nonlinear and linear networks.