Some algorithmic problems of linear network solvability

The existence of a normal tree is known to be a necessary condition for the unique solvability of a network according to Milic´s (1974) theorem. However, really efficient algorithms for finding such a tree were given only more recently, using the theory of polymatroid matching. This tool can be used for more general algorithms as well, taking every pathological 2-port into consideration. As a byproduct, a short proof to Milic´s theorem has also been obtained