The liar paradox and fuzzy logic
Petr Hájek, Jeffrey Bruce Paris, John C. Shepherdson · Journal of Symbolic Logic · 2000
Abstract Can one extend crisp Peano arithmetic PA by a possibly many-valued predicate Tr(x) saying “xis true” and satisfying the “dequotation schema” for all sentences φ? This problem is investigated in the frame of Łukasiewicz infinitely valued logic.