Write a function which takes a list of numbers and returns a list of tuples that is a subset of product of the list with itself and first member of each tuple is less than or equall to the second one.
In mathematical terms:
A x A = {(x,y)| x∈A and y∈A}
{(x,y)| x>=y, (x,y) ∈ A x A }
relation_list([0, 1, 2, 3]) ➞ [(0, 0), (0, 1), (0, 2), (0, 3), (1, 1), (1, 2), (1, 3), (2, 2), (2, 3)]
relation_lst([858, 544, 164]) ➞ [(164, 164), (164, 544), (164, 858), (544, 544), (544, 858), (858, 858)]
relation_lst([-1]) ➞ [(-1, -1)]
relation_lst([0]) ➞ [(0, 0)]
relation_lst([]), []
The result should be in ascending order.