Program.qs

namespace ExploreEntanglement {
    open Microsoft.Quantum.Canon;
    open Microsoft.Quantum.Intrinsic;
    open Microsoft.Quantum.Diagnostics;
    open Microsoft.Quantum.Measurement;

    operation SetQubitState(desired : Result, target : Qubit) : Unit {
        if desired != M(target) {
            X(target);
        }
    }
    
    @EntryPoint()
    operation TestBellState(count : Int, initial : Result) : (Int, Int, Int, Int) {
    mutable numOnesQ1 = 0;
    mutable numOnesQ2 = 0;

    // allocate the qubits
    use (q1, q2) = (Qubit(), Qubit());   
    for test in 1..count {
        SetQubitState(initial, q1);
        SetQubitState(Zero, q2);

        H(q1);
        CNOT(q1, q2);                   // added CNOT operation
        
        // measure each qubit
        let resultQ1 = M(q1);            
        let resultQ2 = M(q2);           

        // Count the number of 'Ones':
        if resultQ1 == One {
            set numOnesQ1 += 1;
            //  set numOnesQ2 += 1;
        }
        // it is possible to delete this logic block beacuse target qubit is dependent on q1 by cnot operation
        if resultQ2 == One {
            set numOnesQ2 += 1;
        }
    }

    // reset the qubits
    SetQubitState(Zero, q1);             
    SetQubitState(Zero, q2);
    

    // Return number of |0> states, number of |1> states
    Message("q1:Zero, One  q2:Zero, One");
    return (count - numOnesQ1, numOnesQ1, count - numOnesQ2, numOnesQ2 );

}

}