Mixin class

Need clarification please,

Conceptually, not in practice, is a Mixin class supposed to augment the interface of another base class or the leaf class deriving from them both?

I understand the difference may be small on paper, since a Mixin only makes its purpose apparent through the leaf class which inherits both from its base and the Mixin. But conceptually I can also see the Mixin augmenting its sister base class interface with this.

I'm having trouble understanding which is right?

>is a Mixin class supposed to augment the interface of another base class or the leaf class deriving from them both?
Conceptually you could go with either, though I think the latter is more intuitive.

> Conceptually you could go with either, though I think the latter is more intuitive.

Thanks Prelude.
So, it's possible to still call a Mixin a Mixin, if the sister base class is not an ABC, correct?

EDIT: Scratch that. The answer seems to be obviously yes.