EntityQ7388341· pop 5· linked from 24 articlesS5Sign in to savenormal modal logic with the additional axioms ◻A→A and ◊A→◻◊AConnectionspropositional calculusEntityKripke semanticsEntityphilosophyEntitylogicEntityThomas AquinasEntityGottfried Wilhelm LeibnizEntityInternational Standard Book NumberEntityWayback MachineEntityequivalence relationEntityStanford Encyclopedia of PhilosophyEntitytautologyEntitytransitive relationEntitymodal logicEntityontological argumentEntityreflexive relationEntityAlvin PlantingaEntitysymmetric relationEntityidempotenceEntityNP-completeEntitymodus ponensEntityCategoriesModal logic