INDRZEJCZAK, A. Tautology Elimination, Cut Elimination, and S5. Logic and Logical Philosophy, [S. l.], v. 26, n. 4, p. 461–471, 2017. DOI: 10.12775/LLP.2017.005. Disponível em: https://apcz.umk.pl/LLP/article/view/LLP.2017.005. Acesso em: 16 jan. 2022.