Answer Q3 only.

Q2. [2 marks ] Show that a set S is c.e. iff there exists a partial computable function whose domain is exactly S. 23. [3 marks ] Based on the fact stated in Q2, are we able to associate every c.e. set with a natural number? In other words, are we able to give every c.e. set an index (e.g., a Gdel number)? Explain your answer. Q2. [2 marks ] Show that a set S is c.e. iff there exists a partial computable function whose domain is exactly S. 23. [3 marks ] Based on the fact stated in Q2, are we able to associate every c.e. set with a natural number? In other words, are we able to give every c.e. set an index (e.g., a Gdel number)? Explain your