The forbidden minor characterization of line-search antimatroids of rooted digraphs Original Research Article

An antimatroid is an accessible union-closed family of subsets of a finite set. A number of classes of antimatroids are closed under taking minors such as point-search antimatroids of rooted (di)graphs, line-search antimatroids of rooted (di)graphs, shelling antimatroids of rooted trees, shelling antimatroids of posets, etc. The forbidden minor characterizations are known for point-search antimatroids of rooted (di)graphs, shelling antimatroids of rooted trees and shelling antimatroids of posets. In this paper, we give the forbidden minor characterization of line-search antimatroids of rooted digraphs.