type_def : UNION ID union_body SEMI

def p_type_def_4(t):
    """type_def : UNION ID union_body SEMI"""
    id = t[2]
    body = t[3]
    lineno = t.lineno(1)
    if id_unique(id, 'union', lineno):
        name_dict[id] = union_info(id, body, lineno)