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Questions related to computability theory, a.k.a. recursion theory
-1
votes
Decidability. $\lbrace \langle D \rangle \mid \text{$D$ accepts $a^kb^k$ for some $k > 0$}\r...
Corollary 3.19 from "An Introduction to the Theory of Computation": "A language is decidable if and only if some nondeterministic Turing machine decides it."
You can construct a nondeterministic Turi …
0
votes
Can a Turing machine decide the language $L_\emptyset$ of machines with empty language?
Proof by contradicting $A_{TM}= \{\langle M,w\rangle \mid M \text{ is a Turing Machine which accepts w}\}$, (which we know is undecidable).
Assume the existence of $R_{TM}$, a TM that decides $L_\emp …