def ckm_standard(t12, t13, t23, delta):
c12 = cos(t12)<EOL>c13 = cos(t13)<EOL>c23 = cos(t23)<EOL>s12 = sin(t12)<EOL>s13 = sin(t13)<EOL>s23 = sin(t23)<EOL>return np.array([[c12*c13,<EOL>c13*s12,<EOL>s13/exp(<NUM_LIT>*delta)],<EOL>[-(c23*s12) - c12*exp(<NUM_LIT>*delta)*s13*s23,<EOL>c12*c23 - exp(<NUM_LIT>*delta)*s12*s13*s23,<EOL>c13*s23],<EOL>[-(c12*c23*exp(<NUM_LIT>*delta)*s13) + s12*s23,<EOL>-(c23*exp(<NUM_LIT>*delta)*s12*s13) - c12*s23,<EOL>c13*c23]])<EOL>
r"""CKM matrix in the standard parametrization and standard phase
    convention.

    Parameters
    ----------

    - `t12`: CKM angle $\theta_{12}$ in radians
    - `t13`: CKM angle $\theta_{13}$ in radians
    - `t23`: CKM angle $\theta_{23}$ in radians
    - `delta`: CKM phase $\delta=\gamma$ in radians