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:

    The common notions that we find in credit around us and infused into our souls by our fathers’ seed, these seem to be the universal and natural ones. Whence it comes to pass that what is off the hinges of custom, people believe to be off the hinges of reason.
    Michel de Montaigne (1533–1592)