1. Ibidem
2. Da Costa developed an infinity of paraconsistent propositional calculi, extending them to calculi of attributes with or without equality, theories of descriptions and theories of sets(...). Later, S. Jaskowoski work on discursive logic was continued by several authors, like Da Costa himself. From the 70's on, paraconsistent logic made enormous progress, being cultivated all over the world, not only for its theoretical value but above all for its applications;The year of 1963 can be considered the theoric starting point of Paraconsistent Logic, when Newton Carneiro Affonso da Costa presented his thesis