Articles
natural deduction
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Here’s a tautology in propositional logic: ⊨(P → Q) ∨ (Q → R) Try throwing that into English. Here’s a reading using some propositions I just came up with: “I’ll die if I’m immortal, or I’ll live if I die.” Obviously, neither of those are the case. But this formula, (P → Q) ∨ (Q…