Editorial

Readers are welcome to the second issue of volume 18 of the Journal of the Brazilian Computer Society. This is a special issue with full papers selected from those presented at the Fourth Latin-American Workshop on Cliques in Graphs, which was held in Itaipava, Brazil, in November 2010. The issue has been organized and is introduced by invited editors Celina M. de Figueiredo and Jayme Luiz Szwarcfiter.

This issue also includes, as a final paper, the reprint of an article by Claudio Leonardo Lucchesi, previously published in the Journal of the Brazilian Computer Society in 2001 (volume 7, n. 3), on the contributions of Professor Szwarcfiter to graph theory and computer science. The reason for reprinting it in this issue is two-fold. Only recently we realized the printed version of the original publication truncated the final two pages of the article. We take the opportunity brought about by this special issue to make sure researchers in graph theory and applications gain access to the full version of that paper. It is also reprinted in celebration of Professor Szwarcfiter 70th birthday, as an acknowledgment of his continuing important contributions to the field.