Cut elimination for Cyclic Proofs: A Case Study in Temporal Logic

We consider modal logic extended with the well-known temporal operator ‘eventually’ and provide a cut-elimination procedure for a cyclic sequent calculus that captures this fragment. The work showcases an adaptation of the reductive cut-elimination method to cyclic calculi. Notably, the proposed algorithm applies to a cyclic proof and directly outputs a cyclic cut-free proof without appealing to intermediate machinery for regularising the end proof.