Mathematical logic provides a rigorous framework for analysing the structure of mathematical reasoning, enabling a deep understanding of both formal systems and the nature of proofs. Central to this ...

Modal logic, an extension of classical logic, investigates the modes of truth such as necessity and possibility. Its development has been closely intertwined with advances in proof theory, a field ...

We give a direct proof of admissibility of cut and contraction for the contraction-free sequent calculus G4ip for intuitionistic propositional logic and for a corresponding multi-succedent calculus: ...

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