Paraconsistent logic (da Costa's C_n systems)
Lógica paraconsistente (sistemas C_n de da Costa)
- Date
- 1963 · confidence medium
- Place
- Curitiba, Paraná, Brazil
- Credited to
- Newton da Costa (with Jaśkowski and Asenjo as independent forerunners)
- Field
- Knowledge & symbols
⚠️ Disputed: the sources disagree.
What was discovered
Hierarchical formal systems that tolerate contradictions without making every proposition true, with a negation that does not obey the principle of explosion. Da Costa developed them as an alternative to classical logic.
Stanisław Jaśkowski proposed a discursive logic in 1948 and Florencio Asenjo (Chile) an antinomic logic in 1954-1966; da Costa arrived independently, and the term 'paraconsistent' is due to Miró Quesada (1976).
What it led to
- Brazilian school of non-classical logic
- Applications in artificial intelligence and inconsistent databases
- Philosophical debate on dialetheism