aList = [ [1,2,3,4,5] , aList[1] , aList[1] ]
see aList # print 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5
x = [ 1, 2, x ]
? x # print 1 2 1 2
? len(x) # print 3
? x[1] # print 1
? x[2] # print 2
? x[3] # print 1 2