(set-logic ALL)
(set-info :status sat)
(declare-fun x () String)
(declare-fun y () String)
(declare-fun z () String)
(assert (= (str.rev "ABC") "CBA"))
(assert (= (str.rev "") ""))
(assert (= (str.rev "A") x))
(assert (= (str.rev (str.++ x y)) "BCA"))
(assert (= (str.rev "BC") y))
(check-sat)