(set-logic QF_S) (set-info :status sat) (declare-fun x () String) (declare-fun y () String) (declare-fun z () String) (declare-fun w () String) (declare-fun w1 () String) (declare-fun w2 () String) (assert (= (str.++ x "aaaae") (str.++ "eaaaa" x))) (check-sat)