5. Write a prolog program, insert_nth(item, n, into_list, result) that asserts that result is the list into_list with item inserted as the n‘th element into every list at all levels.

 5. Write a prolog program, insert_nth(item, n, into_list, result) that asserts that result is the list into_list with item inserted as the n‘th element into every list at all levels. 

insert_nth(Item,1,List,[Item|List]).

insert_nth(Item,Pos,[H|List],[H|Result]):-Pos1 is Pos-1,insert_nth(Item,Pos1,List,Result).

OUTPUT:

insert_nth(5,1,[2],X).

X = 2

insert_nth(5,1,[9,8,7,6],Y).

Y = [5, 9, 8, 7, 6]