Definition: A function that cannot be computed by any algorithm --- equivalently, not by any Turing machine.
See also computable, unsolvable problem, intractable, busy beaver.
Note: From Algorithms and Theory of Computation Handbook, page 24-19, Copyright © 1999 by CRC Press LLC. Appearing in the Dictionary of Computer Science, Engineering and Technology, Copyright © 2000 CRC Press LLC.
If you have suggestions, corrections, or comments, please get in touch with Paul Black.
Entry modified 17 December 2004.
HTML page formatted Wed Mar 13 12:42:46 2019.
Cite this as:
Algorithms and Theory of Computation Handbook, CRC Press LLC, 1999, "uncomputable function", in Dictionary of Algorithms and Data Structures [online], Paul E. Black, ed. 17 December 2004. (accessed TODAY) Available from: https://www.nist.gov/dads/HTML/uncomputableFunction.html