Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
Undecidable problems are computational problems for which there is no algorithm that can always provide a correct answer. In other words, these are problems that cannot be solved by any computer program.
The halting problem refers to the computational problem of determining whether a given program will terminate or run forever.
Turing Machine: A Turing machine is an abstract model used for studying computability and complexity theory. It represents a hypothetical computing device that can manipulate symbols on an infinite tape according to a set of rules.
Gödel's Incompleteness Theorems: Gödel's incompleteness theorems are two fundamental results in mathematical logic that show there are statements within formal systems that cannot be proven or disproven using those systems alone. These theorems have implications for undecidability in mathematics and computer science.