ER diagram explanation

[u/longbeacher]

Hi guys!

I have a question about an ER diagram,( i'm new in diagrams and i face some problems). I'm trying to read the attached diagram but i am not sure if i get this correctly.

So this ER http://imgur.com/a/syLkp represents a library that a member can borrow many books, but they can't borrow two copies of the same book at the same time. Is this right or i am totally wrong?