$ z3 test.smt2 
sat
Segmentation fault (core dumped)
$ cat test.smt2
(declare-datatypes ((T_A 1))
   ((par (T) (
      (cc_a (x (T_A (T_A T))))
      (cc_b)
     ))
))
(declare-fun t1 () (T_A Int))
(check-sat)
(get-model)