code: def uddd(self, rho, sigma, mu, nu):
      G = self.G
      x = self.x
      r = G.udd(rho, nu, sigma).diff(x[mu]) - G.udd(
          rho, mu, sigma
      ).diff(x[nu])
      for lam in [0, 1, 2, 3]:
          r += G.udd(rho, mu, lam) * G.udd(lam, nu, sigma) - G.udd(
              rho, nu, lam
          ) * G.udd(lam, mu, sigma)
      return r
  
imports: from sympy import exp, Symbol, sin, dsolve, Function, Matrix, Eq, pprint, solve
label_desc: Use image node_id 2 for calling the Riemann obj's underlying member method code with example usage: obj.uddd(rho, sigma, mu, nu) and returns: r