On Terminal Delta-Wye Reducibility of Planar Graphs

摘要

We prove terminal Δ-Y reducibility of planar graphs with at most three terminals. The most important consequence of our proof is that this implicitly gives an efficient algorithm with time complexity O(|E(G)|4) for reducibility of planar graphs G with at most three terminals. It also can be used for restricted reducibility problems with more terminals. Our proof uses a very well-known translation from these operations to transformations on the medial graph.