When disambiguating as far as possible, löb becomes □(□B → A) → □A, but □löb becomes □(□(□B → A) → □B). Perhaps Ψ has a universal property related to this?
When disambiguating as far as possible, löb becomes □(□B → A) → □A, but □löb becomes □(□(□B → A) → □B). Perhaps Ψ has a universal property related to this?