(self)
return self.cartan_type.cartan_matrix()
Return the Cartan matrix of Lie algebra associated
        with this root system.

        Example
        =======
        >>> from sympy.liealgebras.root_system import RootSystem
        >>> c = RootSystem("A3")
        >>> c.cartan_matrix()
        Matrix([
            [ 2, -1,  0],
            [-1,  2, -1],
            [ 0, -1,  2]])
Return the Cartan matrix of Lie algebra associated
        with this root system.
Return the Cartan matrix of Lie algebra associated with this root system .
def cartan_matrix(self):
        """
        Return the Cartan matrix of Lie algebra associated
        with this root system.

        Example
        =======
        >>> from sympy.liealgebras.root_system import RootSystem
        >>> c = RootSystem("A3")
        >>> c.cartan_matrix()
        Matrix([
            [ 2, -1,  0],
            [-1,  2, -1],
            [ 0, -1,  2]])
        """
        return self.cartan_type.cartan_matrix()
def cartan_matrix ( self ) : return self . cartan_type . cartan_matrix ( )