Dynamic Modal Logic
Dynamic modal logic explores necessary and possible connections between events. It extends…
Dual of a Truth-Table and Formulas
The dual of a truth-table involves swapping truth values. Connectives like conjunction…
Doxastic Modal Logic: The Logic of Belief
Doxastic modal logic explores the reasoning behind beliefs. It models how rational…
Downward Löwenheim–Skolem Theorem
The downward Löwenheim–Skolem theorem states that if a theory has an infinite…
Double Turnstile Symbol (⊨) in Logic
The double turnstile (⊨) symbol signifies semantic entailment or logical consequence. It…
Double Negation Introduction
The principle of double negation introduction states that for any proposition P,…
Double Negation Elimination
Double negation elimination is a core principle in classical logic. It states…
Domain of Discourse: Defining the Scope of Logic
The domain of discourse is the set of all objects under consideration…