Caro Tony, o exemplo mais óbvio e conhecido de falha do Teorema da Dedução ocorre na lógica trivalente L3 de Lukasiewicz:
primeiro, nao vale a "lei de absorção" (p -->(p --> q)) --> (p -->q), o que impede o Teorema da Dedução na forma usual, isto é, não vale: p |- q sse |- p -->q; contudo, vale uma "forma fraca" do Teorema da Dedução: p |- q sse |- p -->(p --> q) . Qualquer dúvida, fale com seus professores :-) Abs, Walter Em 20 de junho de 2011 10:10, Mario Benevides <[email protected]> escreveu: > Dear Tony, > > The deduction theorem does not hold for many modal logics. PDL is a > classical example. > > Mario > > Em 17 de junho de 2011 13:36, Tony Marmo <[email protected]> escreveu: > >> Dear Friends, >> >> I write to inquire about an example of logic system to which the >> meta-inference rule does not apply. If you can remember any, please feel >> free to respond this. >> >> By meta-inference rule I mean: >> >> If A,B |- C, then A |- B=>C >> >> Thank you very much. >> _______________________________________________ >> Logica-l mailing list >> [email protected] >> http://www.dimap.ufrn.br/cgi-bin/mailman/listinfo/logica-l >> > > > > -- > Federal University of Rio de Janeiro > www.cos.ufrj.br/~mario > _______________________________________________ > Logica-l mailing list > [email protected] > http://www.dimap.ufrn.br/cgi-bin/mailman/listinfo/logica-l > -- ++++++++++++++++++++++++++++++++++++ Prof. Dr. Walter Carnielli Director Centre for Logic, Epistemology and the History of Science – CLE State University of Campinas –UNICAMP 13083-859 Campinas -SP, Brazil Phone: (+55) (19) 3521-6517 Fax: (+55) (19) 3289-3269 e-mail: [email protected] Website: http://www.cle.unicamp.br/prof/carnielli _______________________________________________ Logica-l mailing list [email protected] http://www.dimap.ufrn.br/cgi-bin/mailman/listinfo/logica-l
