1. Computer Science Department, CINVESTAV-IPN, Mexico City, 07360, Mexico jfalcon@computacion.cs.cinvestav.mx
2. LIACS, Leiden University, Leiden, 2333, The Netherlands m.t.m.emmerich@liacs.leidenuniv.nl
3. Computer Science Department, CINVESTAV-IPN, Mexico City, 07360, Mexico Basque Center for Applied Mathematics (BCAM) & Ikerbasque, Spain ccoello@cs.cinvestav.mx