APPEND.html -- ACL2 Version 6.3

### APPEND

concatenate zero or more lists

    Major Section:  ACL2-BUILT-INS

`Append`, which takes zero or more arguments, expects all the arguments except perhaps the last to be true (null-terminated) lists. It returns the result of concatenating all the elements of all the given lists into a single list. Actually, in ACL2 `append` is a macro that expands into calls of the binary function `binary-append` if there are at least two arguments; if there is just one argument then the expansion is that argument; and finally, `(append)` expands to `nil`.

`Append` is a Common Lisp function. See any Common Lisp documentation for more information.