KnowraProof by contradictionLinked fromLinked fromThe 22 pages that link to Proof by contradiction, each with the reason it gives.All 22Broader topic 3Related 9Narrower topic 3Compared with 7Pigeonhole principleRelated: Assuming every container stays below a proposed occupancy bound often contradicts the total count.Irrational numberRelated: The classic proof for the square root of two assumes a rational fraction and reaches impossible parity.Law of Excluded MiddleRelated: Classical versions can rely on excluded-middle reasoning to establish claims indirectly.TheoremRelated: It proves a theorem by showing that denying its conclusion conflicts with established facts.Uncountable setRelated: Uncountability proofs often assume a complete enumeration and contradict it.Existence theoremRelated: It can establish existence indirectly by ruling out the possibility that no object qualifies.Wilson's theoremRelated: The converse can be proved by assuming n is composite and examining a proper divisor.Discrete mathematicsRelated: It establishes many discrete results by ruling out impossible configurations.Consequentia mirabilisRelated: The principle can be derived by assuming the proposition false and using its consequence to reach a contradiction.