Por Borja Sierra Miranda (University of Bern).
In [1], we provided a method for eliminating cuts in non-wellfounded proofs with a local-progress condition, these being the simplest kind of non-wellfounded proofs. The method consisted of splitting the proof into nicely behaved fragments. This paper extends our method to proofs based on simple trace conditions. The main idea is to split the system with the trace condition into infinitely many local-progress calculi that together are equivalent to the original trace-based system. This provides a cut-elimination method using only basic tools of structural proof theory and corecursion, which is needed due to working in a non-wellfounded setting. We will employ our method to obtain syntactic cut-elimination for K+, a system of modal logic with the master modality.
References:
- [1]: Borja Sierra Miranda, Thomas Studer and Lukas Zenger. "Coalgebraic Proof Translations of Non-Wellfounded Proofs". In Agata Ciabattoni, David Gabelaia and Igor Sedlár (eds). (2024) Advances in Modal Logic, Vol. 15. College Publications.
Transmissão via Zoom (pw: 919 4789 5133).