Naive set theory with extensionality in partial logic and in paradoxical logic. (English) Zbl 0801.03019
Summary: Two distinct and apparently “dual” traditions of non-classical logic, three-valued logic and paraconsistent logic, are considered here and a unified presentation of “easy-to-handle” versions of these logics is given, in which full naive set theory, i.e. Frege’s comprehension principle + extensionality, is not absurd.
MSC:
03B50 | Many-valued logic |
03B53 | Paraconsistent logics |
03E70 | Nonclassical and second-order set theories |