If I have class B : A {}
I say that "Class B inherited class A" or "class B derives from class A".
However, if I instead have:
class B : ISomeInterface {}
it's wrong to say "B inherits ISomeInterface" -- the proper term is to say "B implements ISomeInterface".
But, say I have
interface ISomeInterface : ISomeOtherInterface {}
Now, it's still wrong to say "inherits", but it's now just as wrong to say "implements" since ISomeInterface doesn't implement anything.
So, what do you call that relationship?