Number9 code inML language

Write a Code (and explain your code)in ML Programming Language Define a function take_first:('a* 'b) list rightarrow prime a list which takes in input list of pairs and gives back the list consisting of the first elements only. Examples: take_first take first [] = [] take_first [(1, 2), (1, 3)] = [1, 1] take_first [(1, "a"), (2, "b"), (3, "c")] = [1, 2, 3], take - first [([], "a", ([1], "b"), ([1, 2], "c")] = [[], [1], [1, 2]]