Matroids and antimatroids-a survey

Similarities and differences between matroids (abstract dependence systems) and antimatroids (abstract convexity systems) are discussed and several analogous characterizations of these structures are compared. While both structures are subclasses of greedoids and arise (in different ways) from common structures (e.g. graphs, finite collections of points in Rn), no relation analogous to matroid duality exists for antimatroids. © 1989.