Abstract :
In this paper we introduce a new class of graphs which generalize both the tolerance and the trapezoid graphs, the multitolerance graphs. We show that the difference between the pathwidth and the treewidth of a multitolerance graph is at most one, and we develop an algorithm which solves the minimum fill-in problem for a multitolerance graph with a given representation in polynomial time. These results complement the recent results of Habib and Möhring [18, 25] about the treewidth and pathwidth of cocomparability graphs and graphs without asteroidal triples, and those of Kloks et al. [21] about the minimum fill-in problem.
