METRIC PROPERTIES OF INCOMPARABILITY GRAPHS WITH AN EMPHASIS ON PATHS

We describe some metric properties of incomparability graphs. We consider the problem of the existence of infinite paths, either induced or isometric, in the incomparability graph of a poset. Among other things, we show that if the incomparability graph of a poset is connected and has infinite diameter, then it contains an infinite induced path. Furthermore, if the diameter of the set of vertices of degree at least 3 is infinite, then the graph contains as an induced subgraph either a comb or a kite.