Write a recursive definition for each of the following a) The operator * on any alphabet such as . b) The operator unary + on

 Write a recursive definition for each of the following
a) The operator * on any alphabet such as Σ.
b) The operator unary + on any alphabet such as Σ.
 c) Reverse of a word such as w define on any alphabet such as Σ.
 We represent the reverse of w with wR, which is the symbols of w  written in the reverse order. Example: w =abb ⟹ wR =bba

d) The set of strings on any alphabet such as Σ, which are  palindrome. Palindrome strings are read the same forward and backward.
 e) The set of strings, which has the same number of ‘a’s and ‘b’s on Σ = {a, b}.