def cartan_matrix(self):

        m = Matrix( 4, 4, [2, -1, 0, 0, -1, 2, -2, 0, 0,
            -1, 2, -1, 0, 0, -1, 2])
        return m
:type callback: Callable(check_handle: check)
dataset/ETHPy150Open sympy/sympy/sympy/liealgebras/type_f.py/TypeF.cartan_matrix--crossover with--dataset/ETHPy150Open veegee/guv/pyuv_cffi/__init__.py/Check.start