@techreport{Report-309-1991,
Title = {Tolerance Graphs and Orders},
Author = {Stefan Felsner},
Booktitle = {Lecture Notes in Computer Science No.\ 657, 1993},
Pages = {17-26},
Year = {1991},
Number = {309},
Editor = {E.W. Mayr},
Publisher = {Springer-Verlag},
Type = {Preprint},
Institution = {Technische Universit\"at Berlin, Institut f\"ur Mathematik},
Abstract = {We show that a tolerance graph that is the complement of a comparability graph is a trapezoid graph, i.e., the complement of an order of interval dimension at most 2. As consequences we are able to give obstructions for the class of bounded tolerance graphs and to give an example of a graph which is alternatingly orientable but not a tolerance graph. We also characterize the tolerance graphs among the complements of trees.}
}