6. Consider the following program specification and implementation for determin- ing if a string is a palindrome: isPalindrome (A,b,e) where input is a string A = doa ... An, and b and e are integers where 0 e then return true 3 CS-MATH 240: Spring 2021 (2) if ab + de then return false (3) return Is Palindrome (A,b+1,e-1) {output is true if A is a palindrome, false otherwise} (a) Trace the execution of each of these calls to IsPalindrome: Is Palindrome("racecar," 0, 6) IsPalindrome(noon, 0, 3) Is Palindrome("skulks," 0,5) (b) Prove the correctness of the IsPalindrome algorithm by arguing (i) partial correctness and (ii) termination