Answer:
a) Let a be 7.Basic step: a ∈ S and a>=0. Recursive Step: a*7i ∈ S where i<=n, and S is the required set
b) Let λ be the empty string. Basis Step: λ ∈ S. Recursive Step: b ∈ S =⇒ 00b ∈ S & 01b ∈ S, and S is the required set
Explanation:
Please check the answer section.