A constructive characterisation of circuits in the simple (2,1)‐sparse matroid
A constructive characterisation of circuits in the simple (2,1)‐sparse matroid
Abstract A simple graph is a (2, 1)‐circuit if and for every proper subgraph H of G . Motivated, in part, by ongoing work to understand unique realisations of graphs on surfaces, we derive a constructive characterisation of (2, 1)‐circuits. The characterisation uses the well‐known 1‐extension and X ‐replacement operations …