Natural Deduction

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:

    Surely knowledge of the natural world, knowledge of the human condition, knowledge of the nature and dynamics of society, knowledge of the past so that one may use it in experiencing the present and aspiring to the future—all of these, it would seem reasonable to suppose, are essential to an educated man. To these must be added another—knowledge of the products of our artistic heritage that mark the history of our esthetic wonder and delight.
    Jerome S. Bruner (20th century)