Python Write a function def single_value(a): a is a sorted list left to right, small to big. The function returns True if the list a is not empty and all elements in a are equal. Otherwise False is returned. Example : Single_value([5, 5, 5, 5,5,5, 5])==True Single_value([5, 5, 5, 5, 5, 5, 6])==False Requirements : Use Top Down, as we have learned and discussed in class