I have some questions about UML.
Given the following Class Diagram and Object Diagram:

Is it allowed to create in the OD two Persons for the r2d2 Robot ?

Object Diagram:(https://i.sstatic.net/825ydAyT.png)
Class Diagram: (https://i.sstatic.net/FH2QQMVo.png)

And is it allowed to do a composition from an interface to a class?
For example in this class diagram: (https://i.sstatic.net/fXNltH6t.png)

Thank you in advance.

1. I dont think it is possible since there is a 0..1 multiplicity on the person side. So every robot only should have zero or one person.

2. I think it is fine, because you then have to implement the interface description for your class.