In logic and proof theory, natural deduction is a kind of proof calculus in which logical reasoning is expressed by inference rules closely related to the "natural" way of reasoning. This contrasts with the axiomatic systems which instead use axioms as much as possible to express the logical laws of deductive reasoning.
Read more about Natural Deduction: Motivation, Judgments and Propositions, Introduction and Elimination, Hypothetical Derivations, Consistency, Completeness, and Normal Forms, First and Higher-order Extensions, Proofs and Type-theory, Classical and Modal Logics
Famous quotes containing the word natural:
“Fielding being mentioned, Johnson exclaimed, “he was a blockhead ....” BOSWELL. “Will you not allow, Sir, that he draws very natural pictures of human life?” JOHNSON. “Why, Sir, it is of very low life. Richardson used to say, that had he not known who Fielding was, he should have believed he was an ostler.””
—Samuel Johnson (1709–1784)