Logic

Entailment: Understanding Logical Necessity

Entailment defines the logical connection where true premises guarantee a true conclusion. It's fundamental to deductive reasoning, ensuring that if…

5 days ago

Elimination Rule in Logical Inference

An elimination rule in logic simplifies formulas by removing connectives or quantifiers. It's crucial for deriving conclusions from premises, forming…

5 days ago

Elimination of Quantifiers

A technique in mathematical logic to remove quantifiers from formulas, preserving logical equivalence. Crucial in theories like real closed fields…

5 days ago

Elementary Equivalence in Logic and Mathematics

Elementary equivalence signifies that two structures share all the same first-order sentences. This concept is crucial in model theory for…

5 days ago

Effectively Decidable Theory

An effectively decidable theory is a formal system where an algorithm can definitively prove any statement as either true or…

5 days ago

Dynamic Modal Logic

Dynamic modal logic explores necessary and possible connections between events. It extends traditional modal logic to analyze how states change…

5 days ago

Dual of a Truth-Table and Formulas

The dual of a truth-table involves swapping truth values. Connectives like conjunction and disjunction are dual. The dual of a…

5 days ago

Doxastic Modal Logic: The Logic of Belief

Doxastic modal logic explores the reasoning behind beliefs. It models how rational agents form and update their beliefs, providing a…

5 days ago

Double Turnstile Symbol (⊨) in Logic

The double turnstile (⊨) symbol signifies semantic entailment or logical consequence. It indicates that the truth of certain propositions guarantees…

5 days ago

Double Negation Introduction

The principle of double negation introduction states that for any proposition P, P implies the double negation of P (¬¬P).…

5 days ago