Abstract
Non-classical solutions to semantic paradox can be associated with conceptions of paradoxicality
understood in terms of entailment facts. In a K3-based theory of truth, for example, it is prima
facie natural to say that a sentence φ is paradoxical iff φ ∨ ¬φ entails an absurdity. In a
recent paper, Julien Murzi and Lorenzo Rossi exploit this idea to introduce revenge paradoxes
for a number of non-classical approaches, including K3. In this paper, I show that on no
understanding of ‘is paradoxical’ (for K3) should both rules needed for their paradox be expected
to hold unrestrictedly. Just which rule fails, however, depends on various factors, including
whether the derivability relation of a target system of reasoning is arithmetically definable.