Elias Humberto Alves, Brazilian logician and philosopher (Guaranésia, Minas Gerais State 17 February 1936 – São Paulo 04 November 2013)

Demonstrated the independence of axioms of the propositional calculus C₁ axioms (1976)

Introduced the first systems of natural deduction for the logics Cn

Developed higher-order versions of Da Costa paraconsistent predicate logics

Solved definitely the problem of the decidability of logics Cn based on the semantics of quasi-matrices (1976)

Demonstrated the decidability of the propositional logics Cn (1976)

With A. Loparic modified certain conditions in valuation definition (1980)

With A. Loparic introduced a bivalent semantics and a decision method for Da Costa logics Cω (1980)

LINKS

http://www.uff.br/ebl/slides/elias_alves.pdf