Good morning/afternoon/evening/night

I'm new to stata and I'm trying to generate a dummy variable from a variable called abc. This variable was a question and from this question I would like two answers to be given the value '1' and the other answers the value '0'.
The values of these answers that need to be given a '1' are 1 and 4. I tried to do: gen abc1=1 if abc==1 & 4, but this did not work. Does anyone know how to do this?

Thank you in advance