Geach Axiom
ID: 07bd5c70-69e2-458e-958f-1122abeb6815 REVIEW_SCORE: 0.0 MTIME: [2024-12-25 Wed 15:55]
Modal logic axiom extending S4. Gives you the light-cone - i.e. causal arrows between points in space-time. benthemmodal2010, p97, is where I first came across it; proved in goldblattDiodoreanModalityMinkowski1980
This node is a singleton!