What’s the line between medium and large format?

I’ve been recently wondering about the distinction between large format and medium format photography. What are your definitions and where do you draw the line? Which of these setups would you consider large format photography as opposed to medium format?

1. 5x7 view camera with a 6x17 film back
2. 4x5 view camera with a 6x12 film back
3. 4x5 view camera with a Phase One digital back
4. 4x5 view camera with a 4x5 digital back
5. 6x12 camera with a helicoid and a large format lens
6. 6x17 view camera, like Shen Hao
7. 6x17 viewfinder camera, like Fuji G617
8. 4x5 “point and shoot” camera without any movements