## A Note on “A linear-size zero-one programming model for the minimum spanning tree problem in planar graphs”

In the paper “A linear-size zero-one programming model for the minimum spanning tree problem in planar graphs” (Networks 39(1):53–60, 2002), Williams introduced an extended formulation for the spanning tree polytope of a planar graph. This formulation is remarkably small (using only $O(n)$ variables and constraints) and remarkably strong (defining an integral polytope). In this note, … Read more