Simpler proof of the theorem by Pusey, Barrett, and Rudolph on the reality of the quantum state

Abstract: The theorem of Pusey, Barrett, and Rudolph proves that different quantum states describe different physical realities. Their proof is based on the construction of entanglement measurement bases of two, and more than two qbits. In this note, I show that a two-qubit entanglement base is sufficient for a general proof.