ABSTRACT
ANA TERESA MARTINS Federal University of Ceara, P.O.Box 12166, Fortaleza, CE, Brazil 60455-760 anaQlia.ufc.br MARCELINO PEQUENO Federal University of Ceara, P.O.Box 12166, Fortaleza, CE, Brazil 60455-760 marcelQlia.ufc.br TARCi'SIO PEQUENO Federal University of Ceara, P.O.Box 12166, Fortaleza, CE, Brazil 60455-760 tarcisioSlia.ufc.br
1 INTRODUCTION The formalization of reasoning under conditions of incomplete knowledge has been a stimulating problem for Artificial Intelligence researchers. By incomplete knowledge, it is meant the property of not being able to decide some especially relevant questions that 'ought' to be decided for practical purposes.
