Vasek Chvatal (Concordia University, Montreal, Canada)

Betweenness

Abstract:
   The ternary relation of betweenness comes up in diverse settings. One is the posthumously published book of Hans Reichenbach, where he attempts to argue about the direction of time through the concept of "causal betweenness", a ternary relation defined on a set of events in a probability space. Baoyindureng Wu and I designed an efficient algorithm to recognize abstract ternary relations isomorphic to Reichenbach's causal betweenness. I will present this algorithm and, if time permits, talk about betweenness in the context of abstract convexity.