2020-01-212020-01-212005SANZ, Wagner Campos. A natural deduction system preserving falsity. Energeia, Buenos Aires, v. 4, n. 1, p. 215-220, 2005.e- 1666-5732http://repositorio.bc.ufg.br/handle/ri/18536This paper presents a natural deduction system preserving falsity. This new system will provide us with means of reviewing a criticism made several years ago by Prior, directed against the semantical definition of logical constants by introduction and elimination rules.engAcesso AbertoNatural deductionFalsityFalsity preservationLogical constantsArtigo