Demystifying $μ$
Bahareh Afshari, Graham E. Leigh, Guillermo Menéndez Turata · Fundamenta Informaticae · 2025
We explore the theory of illfounded and cyclic proofs for the propositional modal $μ$-calculus. A fine analysis of provability for classical and intuitionistic modal logic provides a novel bridge between finitary, cyclic and illfounded conceptions of proof and re-enforces the importance of two normal form theorems for the logic: guardedness and disjunctiveness.