Evaluating_App_on_Sample_Input.html -- ACL2 Version 6.3

## Evaluating App on Sample Input

    ACL2 !>(app nil '(x y z))
    (X Y Z)

    ACL2 !>(app '(1 2 3) '(4 5 6 7))
    (1 2 3 4 5 6 7)

    ACL2 !>(app '(a b c d e f g) '(x y z))   ; click here for an explanation
    (A B C D E F G X Y Z)

    ACL2 !>(app (app '(1 2) '(3 4)) '(5 6))
    (1 2 3 4 5 6)

    ACL2 !>(app '(1 2) (app '(3 4) '(5 6)))
    (1 2 3 4 5 6)

    ACL2!>(let ((a '(1 2))
                (b '(3 4))
                (c '(5 6)))
            (equal (app (app a b) c)
                   (app a (app b c))))
    T

As we can see from these examples, ACL2 functions can be executed more or less as Common Lisp.

The last three examples suggest an interesting property of `app`.