I think nmr is quite correct. I'm teaching my HCI software engineering course, and I need to encourage students to stop thinking of "Business Logic" and think more about MVC.
Quite often, their previous professors would tell them that,
"Underneath the HCI is the BIDness Logic"
Can we please LOSE the business logic? Since software rarely has NO user interface,
we can say, for the rest of the software, there is the View, the user Control, and the Model.
And there will be message passing between these three entities. Which are, by the way, "output", "input"/"state". Just as Turing (and Church) had taught us.
So... let's lose 'the bidness logic'