1409-2433 1409-2433 S1409-24332021000200237 10.15517/rmta.v28i2.44748 Mexico Mexico Mexico 00 12 2021 00 12 2021 28 2 237 259

2012 17 5 5 451-78 2002 Pure and Applied Mathematics Series 2003 2nd Applied Mathematical Sciences 2004 Graduate Texts in Mathematics 1991 2002 2 393-460 Texts in Applied Mathematics 2008