Progress in Artificial Intelligence : 13th Portuguese Conference on Artificial Intelligence, EPIA 2007, Workshops: GAIW, AIASTS, ALEA, AMITA, BAOSW, BI, CMBSB, IROBOT, MASTA, STCS, and TEMA, Guimarães, Portugal, December 3-7, 2007, Proceedings - José Neves, Manuel Filipe Santos, José Manuel Machado ((Lecture Notes in Computer Science))