Q. Let L1 be a recursive language. Let L2 and L3 be languages that are recursively enumerable but not recursive. Which of the following statements is not necessarily true? (Solved)
1. L2 – L1 is recursively enumerable.
2. L1 – L3 is recursively enumberable
3. L2 intersection L1 is recursively enumberable
4. L2 union L1 is recursively enumberable
- b. L1 – L3 is recursively enumberable