I did not say that it is not possible to do it. I said it is counterintuitive for me to express or model it in that way. And as you can see in the discussion a

I did not say that it is not possible to do it. I said it is counterintuitive for me to express or model it in that way. And as you can see in the discussion arising, even this simple example is becoming a complex modelling problem in OOP.