The thesis that, in a system of natural deduction, the meaning of a logical constant is given by some or all of its introduction and elimination rules has been developed recently in the work of ...

This paper concerns modal logics of provability -- Gödel-Löb system GL and Solovay logic S -- the smallest and the greatest representation of arithmetical theories in propositional logic respectively.

The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their ...