private boolean r_factive() {
            int among_var;
                    // (, line 132
                    // [, line 133
                    ket = cursor;
                    // substring, line 133
                    among_var = find_among_b(a_7, 2);
                    if (among_var == 0)
                    {
                        return false;
                    }
                    // ], line 133
                    bra = cursor;
                    // call R1, line 133
                    if (!r_R1())
                    {
                        return false;
                    }
                    switch(among_var) {
                        case 0:
                            return false;
                        case 1:
                            // (, line 134
                            // call double, line 134
                            if (!r_double())
                            {
                                return false;
                            }
                            break;
                        case 2:
                            // (, line 135
                            // call double, line 135
                            if (!r_double())
                            {
                                return false;
                            }
                            break;
                    }
                    // delete, line 137
                    slice_del();
                    // call undouble, line 138
                    if (!r_undouble())
                    {
                        return false;
                    }
                    return true;
                }