undecidable
Beyond formal proof
Undecidable describes a problem or proposition that cannot be resolved by any systematic method.
In mathematics and logic, an undecidable statement is one that can neither be proved nor disproved within a given formal system: Gödel showed that any sufficiently powerful system contains undecidable propositions.
In computer science, an undecidable problem has no algorithm guaranteed to produce a correct answer for all inputs.
Marked by hesitation
- computabilityAlgorithmic solvability of problems
- algorithmFinite problem-solving procedure
- recursionProcess invoking itself
- recursiveDefined in terms of itself
Turing · unsolvable · intractable · Church · enumerable · computable · word problem · Rice
State of lacking parts
- theoremDemonstrated logical conclusion
- proofDemonstration of truth
- axiomSelf-evident starting principle
- paradoxSeemingly absurd truth
formalism · proposition · sentence · statement · self-reference · consistency · decidability · provability
Lacking final determination
- unsettledNot yet resolved
- openNot closed
- pendingAwaiting resolution or decision
- inconclusiveNot yielding a decision
undetermined · uncertain · indefinite · open-ended · unsolved · unascertained · unestablished · tentative
halting
Marked by hesitation
- computabilityAlgorithmic solvability of problems
- algorithmFinite problem-solving procedure
- recursionProcess invoking itself
Turing · recursive · unsolvable · intractable · Church · enumerable · computable · word problem · Rice · oracle
incompleteness
State of lacking parts
- theoremDemonstrated logical conclusion
- proofDemonstration of truth
- axiomSelf-evident starting principle
paradox · formalism · proposition · sentence · statement · self-reference · consistency · decidability · provability · unprovable
unresolved
Lacking final determination
inconclusive · undetermined · uncertain · indefinite · open-ended · unsolved · unascertained · unestablished · tentative · ambiguous
- Complexity ClassesP, NP, EXP, NL, L
- validityvalid, invalid, true, false, correct
- Algorithm Analysisruntime, running time, growth rate, complexity, linear
undecidabledecidable
Algorithmically resolvable
computable · solvable · recursive · tractable · calculable
undecidabledecidable
Algorithmically resolvable
determinable · resolvable · settleable · answerable · certain
decide, decision, decided, deciding, decisive, indecisive, undecided, indecision, decisiveness