enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Contradiction - Wikipedia

    en.wikipedia.org/wiki/Contradiction

    In classical logic, particularly in propositional and first-order logic, a proposition is a contradiction if and only if. Since for contradictory φ {\displaystyle \varphi } it is true that ⊢ φ → ψ {\displaystyle \vdash \varphi \rightarrow \psi } for all ψ {\displaystyle \psi } (because ⊥ ⊢ ψ {\displaystyle \bot \vdash \psi } ), one ...

  3. Proof by contradiction - Wikipedia

    en.wikipedia.org/wiki/Proof_by_contradiction

    In logic, proof by contradiction is a form of proof that establishes the truth or the validity of a proposition by showing that assuming the proposition to be false leads to a contradiction. Although it is quite freely used in mathematical proofs, not every school of mathematical thought accepts this kind of nonconstructive proof as universally ...

  4. Law of noncontradiction - Wikipedia

    en.wikipedia.org/wiki/Law_of_noncontradiction

    In logic, the law of non-contradiction (LNC) (also known as the law of contradiction, principle of non-contradiction (PNC), or the principle of contradiction) states that contradictory propositions cannot both be true in the same sense at the same time, e. g. the two propositions " p is the case " and " p is not the case " are mutually ...

  5. Law of thought - Wikipedia

    en.wikipedia.org/wiki/Law_of_thought

    Paraconsistent logic' refers to so-called contradiction-tolerant logical systems in which a contradiction does not necessarily result in trivialism. In other words, the principle of explosion is not valid in such logics. Some (namely the dialetheists) argue that the law of non-contradiction is denied by dialetheic logic.

  6. List of logic symbols - Wikipedia

    en.wikipedia.org/wiki/List_of_logic_symbols

    propositional logic, Boolean algebra, first-order logic. ⊥ {\displaystyle \bot } denotes a proposition that is always false. The symbol ⊥ may also refer to perpendicular lines. The proposition. ⊥ ∧ P {\displaystyle \bot \wedge P} is always false since at least one of the two is unconditionally false. ∀.

  7. Tautology (logic) - Wikipedia

    en.wikipedia.org/wiki/Tautology_(logic)

    Here, logical proposition refers to a proposition that is provable using the laws of logic. ... is a contradiction, then tautologically ...

  8. Russell's paradox - Wikipedia

    en.wikipedia.org/wiki/Russell's_paradox

    In mathematical logic, Russell's paradox (also known as Russell's antinomy) is a set-theoretic paradox published by the British philosopher and mathematician Bertrand Russell in 1901. [1][2] Russell's paradox shows that every set theory that contains an unrestricted comprehension principle leads to contradictions. [3]

  9. Principle of explosion - Wikipedia

    en.wikipedia.org/wiki/Principle_of_explosion

    In classical logic, intuitionistic logic, and similar logical systems, the principle of explosion[ a ][ b ] is the law according to which any statement can be proven from a contradiction. [ 1 ][ 2 ][ 3 ] That is, from a contradiction, any proposition (including its negation) can be inferred; this is known as deductive explosion. [ 4 ][ 5 ] The ...