Function REVAPPEND

The function {tt revappend} is similar to append, except that it adds the items in reverse order.
Arity: 3
Axioms:
(Nth-Domain Revappend 3 List)

(Nth-Domain Revappend 2 List)

(Nth-Domain Revappend 1 List)

(=> (Revappend ?L1 ?L2 ?New-List)
    (= ?New-List
       (If (Null ?L1)
           (If (List ?L2) ?L2)
           (Revappend (Rest ?L1) (Cons (First ?L1) ?L2)))))