We present new proofs of cut elimination for intuitionistic, classical, and linear sequent calculi. In all cases the proofs proceed by three nested structural inductions, avoiding...
System SKS is a set of rules for classical propositional logic presented in the calculus of structures. Like sequent systems and unlike natural deduction systems, it has an explici...
We consider an extension of bi-intuitionistic logic with the traditional modalities , , and from tense logic Kt. Proof theoretically, this extension is obtained simply by extendin...
Gentzen’s Hauptsatz – cut elimination theorem – in sequent calculi reveals a fundamental property on logic connectives in various logics such as classical logic and intuition...