[
 (program) {
  (stmt_list) {
   (stmt_or_defined_macro) {
    (stmt) {
     (variable_declaration) {
      (builtintype) {
       int
      }
      (assign) {
       a
       =
       (expr_plus) {
        1
        +
        1
       }
      }
     }
     ;
    }
   }
  }
 }
]