Abstract:

I shall speak about a sequence of posets, which I call the posets of elementary collapses, that are similar, both in origin and in its properties, to the face posets of the associahedron. Some basic properties that are shared with the associahedra will be established; that they are lattices and shellable. Whether or not they, like the face posets of the associahedra, are face posets of some polytopes is an open question.