undecidable

Fetched 2026-10-26 (cache).

Synonyms: undecidably, undeniable, undesirable, undefinable, decidable, undefiable, underivable, undividable, indecimable, undeceivable, undeclinable

Antonyms: undecidably, undeniable, undesirable, undefinable, decidable, undefiable, underivable, undividable, indecimable, undeceivable, undeclinable

Related words from Datamuse; suggestions, not definitions.

Adjective

1. {{lb|en|mathematics|computing theory}} Incapable of being [[algorithm]]ically decided in [[finite]] time. For example, a set of [[string]]s is undecidable if it is impossible to program a [[computer]] (even one with infinite [[memory]]) to determine whether or not specified strings are included.
2. {{lb|en|mathematics}} (''of a [[WFF]]'') [[logically independent]] from the [[axiom]]s of a given theory; i.e., that it can ''never'' be either proved or disproved (i.e., have its negation proved) on the basis of the axioms of the given theory. (''Note:'' this latter definition is independent of any time bounds or computability issues, i.e., more Platonic.)

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