(append list [list ...])
The append function adds lists together and returns a new list. All specified arguments must be lists.
Examples
: (append '(1 2 3)'(4 5 6))
(1 2 3 4 5 6)
: (append '((abc) (def)) '((ghi) (jkl)))
((ABC) (DEF) (GHI) (JKL))