Advances in Artificial Intelligence - SBIA 2012 21th Brazilian Symposium on Artificial Intelligence, Curitiba, Brazil, October 20-25, 2012. Proceedings - Barros, Leliane N.; Finger, Marcelo; Pozo, Aurora T.; Gimenénez-Lugo, Gustavo A.; Castilho, Marcos (Springer Berlin Heidelberg : Imprint: Springer, 2012)