Assertion


تاربرگ‌های پیموده‌شده در این نشست: A⥽(B⥽B) ⟩ Admissible rule ⟩ Absorption ⟩ axiomatization ⟩ A reduction in number of the postulates for C. I. Lewis' system of strict implication ⟩ Axiom of Extensionality