# Protocol for entaglement swapping

Suppose there are 3 parties, of which 2 pairs share an EPR pair and can communicate classically. What is a protocol that results in the third pair sharing an EPR pair?

That is the problem I'm given, I'm lost on how to do it, let alone what it means to "share an EPR pair" in the end.

For two parties to share an EPR pair means that each party has one qubit, and these two qubits together are in state $$\frac{1}{\sqrt{2}}(|00\rangle + |11\rangle)$$ (or one of the other Bell pairs).