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

Let A ≤m B denotes that language A is mapping reducible (also known as many-to-one reducible) to language B. Which one of the following is FALSE? Correct Answer If A ≤_m B and B is not recursively enumerable then A is not recursively enumerable

Concept:

Theorem 1:

If A ≤_m B then:

If B is recursively enumerable then A is recursively enumerable.

If B is recursive then A is recursive.

Theorem 2:

If A ≤_m B then:

If A is not recursively enumerable then B is not recursively enumerable.

If A is not recursive then B is not recursive.

If A is undecidable then B is undecidable.

Hence option 4 is the correct answer and false statement.