Department of Computer Science, Federal University of Minas Gerais, Belo Horizonte, Brazil. raquelcm@dcc.ufmg.br|Department of Computer Science, Federal University of Minas Gerais, Belo Horizonte, Brazil. raquelcm@dcc.ufmg.br|Department of Computer Science, Federal University of Minas Gerais, Belo Horizonte, Brazil. raquelcm@dcc.ufmg.br