[Gretl-users] Single ARIMA Command with Seasonal Differences

Greetings, I have some quarterly data U1 (variable 1) I would like to model the data as an ARIMA process. I take the first difference of U1 to create d_U1 (variable 3) and then take the first difference of d_U1 to create d_d_U1 (variable 4). Finally, I take the seasonal difference to create sd_d_d_U1 (variable 5) and try an ARIMA(0,0,1) model. The Gretl commands are: diff U1 diff d_U1 sdiff d_d_U1 arima 0 0 1 ; 5 I would like to do all of this in one command. I have tried a number of different commands looking something like arima 0 2 1 ; 0 1 0 ; 1 but have been unable to get the same answers as I did doing the evaluation step-by-step. Can someone suggest how I can go about doing this with one command? Tom