Adrián Riesco Alberto Verdejo Narciso Martí-Oliet Rafael Caballero A Declarative Debugger for Maude. 116-121 2008 AMAST http://dx.doi.org/10.1007/978-3-540-79980-1_9 conf/amast/2008 db/conf/amast/amast2008.html#RiescoVMC08