We call it the long friday in Norwegian, so if you have plenty of time, here's my most recent paper on contraction-free sequent calculi for S5 and Carnap's C obtained through local and global metainferential validity: link.springer.com/article/10.1...
This paper develops a sequent calculus framework for representing locally and globally valid metainferences through which contraction-free sequent calculi for the modal logics S5 and the propositional...
