Final answer:
Efficiency of deciders and verifiers in computational complexity theory.
Step-by-step explanation:
(a) For a decider to be efficient, it means that it can determine whether an input belongs to a language or not in a reasonable amount of time.
(b) To prove that a language L∈P, it must be shown that there exists a polynomial-time algorithm that decides L.
(c) For a verifier to be efficient, it means that it can verify the correctness of a solution to a problem in a reasonable amount of time.
(d) An algorithm V must satisfy the criteria of being polynomial-time and have the property of accepting only valid solutions to a problem in order to be an efficient verifier for a language L.
(e) To prove that a language L∈NP, it must be shown that there exists a polynomial-time verifier for L.