halting
131Post–Turing machine — The article Turing machine gives a general introduction to Turing machines, while this article covers a specific class of Turing machines. A Post–Turing machine is a program formulation of an especially simple type of Turing machine, comprising a …
132Proof of impossibility — A proof of impossibility, sometimes called a negative proof or negative result , is a proof demonstrating that a particular problem cannot be solved, or cannot be solved in general. Often proofs of impossibility have put to rest decades or… …
