Manuel A. Cardenete flores Loyola Andalusia University   Avd. Miguel Manaute Humanes #1 Sevilla, Dos Hermanas 41704 Spain   macardenete@uloyola.es   http://www.macardenete.com/?lang=es           JEL Areas: C6 : Mathematical Methods and Programming: General D5 : General Equilibrium and Disequilibrium: General