1 citations · 1 across the 4 of their papers we have counts for
4 papers
When all directed cycles have the same weight
Eli Berger, Daniel Carter, Paul Seymour
A digraph is weightable if its edges can be weighted with real numbers such that the total weight in each directed cycle equals 1. There are several equivalent conditions: that…
The minimal nonplanar strong digraphs
Stephen Bartell, Paul Seymour
Kuratowski's theorem says that the minimal (under subgraph containment) graphs that are not planar are the subdivisions of and of . Here we study the minimal (under…
When all directed cycles have length three
Paul Seymour
We give a construction to build all digraphs with the property that every directed cycle has length three.
Thomassen's theorem on the two-linkage problem in acyclic digraphs: a shorter proof
Paul Seymour
Let G be an acyclic digraph, and let a, b, c, d be vertices, where a, b are sources, c, d are sinks, and every other vertex has in-degree and out-degree at least two. In 1985, Thom…