contrapositive of implication

См. также в других словарях:

• Contraposition — For contraposition in the field of traditional logic, see Contraposition (traditional logic). For contraposition in the field of symbolic logic, see Transposition (logic). Contraposition is a logical relationship between two propositions, or… …   Wikipedia

• Raven paradox — The Raven paradox, also known as Hempel s paradox or Hempel s ravens is a paradox proposed by the German logician Carl Gustav Hempel in the 1940s to illustrate a problem where inductive logic violates intuition. It reveals the problem of… …   Wikipedia

• Transposition (logic) — In the methods of deductive reasoning in classical logic, transposition is the rule of inference that permits one to infer from the truth of A implies B the truth of Not B implies not A , and conversely . [Brody, Bobuch A. Glossary of Logical… …   Wikipedia

• Mathematical proof — In mathematics, a proof is a convincing demonstration (within the accepted standards of the field) that some mathematical statement is necessarily true.[1][2] Proofs are obtained from deductive reasoning, rather than from inductive or empirical… …   Wikipedia

• Deduction theorem — In mathematical logic, the deduction theorem is a metatheorem of first order logic.[1] It is a formalization of the common proof technique in which an implication A → B is proved by assuming A and then proving B from this assumption.… …   Wikipedia

• Modus tollens — Rules of inference Propositional calculus Modus ponens (A→B, A ⊢ B) Modus tollens (A→B, ¬B ⊢ ¬A) …   Wikipedia

• Modus ponens — Rules of inference Propositional calculus Modus ponens (A→B, A ⊢ B) Modus tollens (A→B, ¬B ⊢ ¬A) …   Wikipedia

• List of topics in logic — This is a list of topics in logic.See also: List of mathematical logic topicsAlphabetical listAAbacus logic Abduction (logic) Abductive validation Affine logic Affirming the antecedent Affirming the consequent Antecedent Antinomy Argument form… …   Wikipedia

• Supertask — In philosophy, a supertask is a task occurring within a finite interval of time involving infinitely many steps (subtasks). A hypertask is a supertask with an uncountable number of subtasks. The term supertask was coined by the philosopher James… …   Wikipedia

• contraposition — noun The statement of the form if not Q then not P , given the statement if P then Q . See Also: contrapositive, implication …   Wiktionary

• Converse (logic) — In logic, the converse of a categorical or implicational statement is the result of reversing its two parts. For the implication P → Q, the converse is Q → P. For the categorical proposition All S is P, the converse is All P is S. In neither case …   Wikipedia