5.2.a_list_of_params

int a, int b

                    formal_parameters
                            |
             -------------------------------------
             |      |         |     |            |
            type    |         |   type           |
             |      |         |     |            |
     primitive_type |         |  primitive_type  |
         |          |         |     |            |
        INT     IDENTIFIER  COMMA  INT       IDENTIFIER
         |          |         |     |            |
         int        a         ,    int           b