Turing Machine: RE, REC and Undecidability GATE 2014 Question #9912 with Solution

GATE 2014 · session-2

Theory of ComputationTuring Machine: RE, REC and UndecidabilitymediumMCQ1 mark

Let A ≤ₘ B denote that language A is mapping reducible (also known as many-to-one reducible) to language B. Which one of the following is FALSE?

AIf A ≤ₘ B and B is recursive then A is recursive.BIf A ≤ₘ B and A is undecidable then B is undecidable.CIf A ≤ₘ B and B is recursively enumerable then A is recursively enumerable.DIf A ≤ₘ B and B is not recursively enumerable then A is not recursively enumerable.

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