Incorrect value for quantum value for BCS game

[vprusso]

It appears as if both the upper and lower bounds on the quantum value of a BCS-converted nonlocal game are yielding incorrect values.

For instance, this is the BCS definition of the CHSH game:

c_1 = np.zeros((2, 2))
c_2 = np.zeros((2, 2))

for v_1 in range(2):
    for v_2 in range(2):
        if v_1 ^ v_2 == 0:
            c_1[v_1, v_2] = 1
        else:
            c_2[v_1, v_2] = 1

chsh_bcs_game = NonlocalGame.from_bcs_game([c_1, c_2])

Running the classical value yields the correct value. However, the quantum bounds are not correct:

print(chsh_bcs_game.classical_value())
0.75
print(chsh_bcs_game.commuting_measurement_value_upper_bound())
0.25
print(chsh_bcs_game.quantum_value_lower_bound())
0.25

There also appears to be a deep copy problem here as well. The classical_value function should be making a deep copy of the predicate matrix.