Hello,
I can not make any sens of question d. of ex 3...
First, Eve does a measurement, "the state of the pair is thus left in a product state gamma X delta"
What are gamma and delta ? Two basis that Eve choses ? A notation to denote an (alpha,beta) combination ? If it is the first case, why would Eve measure both of the qubits, and why would we discuss the values that gamma and delta can take (they can take any values in [0, 2pi]? ) ?
Thank you.