Showing papers by "School for Advanced Studies in the Social Sciences published in 1980"
TL;DR: Wu and Liu as discussed by the authors gave a topological proof of a planarity criterium, which consists of associating to each crossing of an embedding of a graph G in the sphere an edge of the graph H associated to G. The graph H is defined by a Tremaux tree of G (maximal depth-first search subtree of G ).
Abstract: W. Wu and Y. Liu have sketched topological proof of a planarity criterium, which consists of associating to each crossing of an embedding of a graph G in the sphere an edge of a graph H associated to G . The graph H is defined by a Tremaux tree of G (maximal depth-first-search subtree of G ). The method is to test whether these edges form a cocycle of H . We give here a complete algebraic proof of their criterium, inspired by Tutte's theory of crossings [9]. The present work can be construed as a more efficient version of Tutte's method.
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