This function enables elements to be inserted into or between lists. Notice that the parameters allow for atoms and lists to be represented. Also, the integer 0 will place an inserted element at the head of a list.
(e-insert '= 0 '(a b c d e f g h i j k l))
=> (= a b c d e f g h i j k l)
(e-insert '= '(3 4 7) '(a b c d e f g h i j k l))
=> (a b = = c d = e f g h i j k l)
(e-insert '(ci gm) '(1 7) '(a b c d e f g h i j k l))