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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def correlator(A, B):
 """Correlators between the probabilities of two parties. :param A: Measurements of Alice. :type A: list of list of :class:`sympy.physics.quantum.operator.HermitianOperator`. :param B: Measurements of Bob. :type B: list of list of :class:`sympy.physics.quantum.operator.HermitianOperator`. :returns: list of correlators. """

    correlators = []
    for i in range(len(A)):
        correlator_row = []
        for j in range(len(B)):
            corr = 0
            for k in range(len(A[i])):
                for l in range(len(B[j])):
                    if k == l:
                        corr += A[i][k] * B[j][l]
                    else:
                        corr -= A[i][k] * B[j][l]
            correlator_row.append(corr)
        correlators.append(correlator_row)
    return correlators