• Dillon Mayhew, Courcelle’s Theorem for hypergraphs

    Room B232 IBS (기초과학연구원)

    Courcelle's Theorem is an influential meta-theorem published in 1990. It tells us that a property of graph can be tested in polynomial time, as long as the property can expressed in the monadic second-order logic of graphs, and as long as the input is restricted to a class of graphs with bounded tree-width. There are

  • Dillon Mayhew, Monadic second-order definability for gain-graphic matroids

    Room B332 IBS (기초과학연구원)

    Every (finite) matroid consists of a (finite) set called the ground set, and a collection of distinguished subsets called the independent sets. A classic example arises when the ground set is a finite set of vectors from a vector space, and the independent subsets are exactly the subsets that are linearly independent. Any such matroid