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:
“It is a dogma of the Roman Church that the existence of God can be proved by natural reason. Now this dogma would make it impossible for me to be a Roman Catholic. If I thought of God as another being like myself, outside myself, only infinitely more powerful, then I would regard it as my duty to defy him.”
—Ludwig Wittgenstein (1889–1951)