Help in assignment

Hi,

my friend asked me if I can help him to finish this homework.

his teacher asked them to make a program in lisp that finds the permutation for a group of numbers
the teacher gave this example
if we give the program {1 2 3} we will get { 3 2 1} {3 1 2} {2 3 1} {2 1 3} { 1 3 2} {1 2 3}

I hope I explained enough
frankly I know nothing about lisp, but I just wanted to help my friend

any help, links to web sites will be appreciated

thanks.