The `append' Function
---------------------
The `append' function attaches one list to another. Thus,
(append '(1 2 3 4) '(5 6 7 8))
produces the list
(1 2 3 4 5 6 7 8)
This is exactly how we want to attach two lengths' lists produced by
`lengths-list-file' to each other. The results contrast with `cons',
(cons '(1 2 3 4) '(5 6 7 8))
which constructs a new list in which the first argument to `cons'
becomes the first element of the new list:
((1 2 3 4) 5 6 7 8)