For the following function, identify the loop invariant, the loop exit condition, and the loop post-condition which shows the algorithm's correctness.

def is_palindrome(string): """ Input: A string Output: True if the string is a palindrome (i.e, same forwards as backwards), False otherwise For example: >>> is_palindrome('abba') True >>> is_palindrome('abca') False """ n = len(string) i = 0 while i < n//2: if string[i] != string[n-i-1]: return False i = i + 1 return True