Undecidable problems are decision problems in computational theory for which no algorithm can be constructed that always leads to a correct yes-or-no answer. In simpler terms, an undecidable problem is one for which it is impossible to devise a general method or a program that can solve all instances of the problem. One of the most famous examples of an undecidable problem is the Halting Problem, which was proven undecidable by Alan Turing in 1936.
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