code: def ud(self, mu, nu):
      r = 0
      for lam in [0, 1, 2, 3]:
          r += self.g.uu(mu, lam) * self.dd(lam, nu)
      return r.expand()
  
imports: from sympy import exp, Symbol, sin, dsolve, Function, Matrix, Eq, pprint, solve
label_desc: Use image node_id 3 for calling the Ricci obj's underlying member method code with example usage: obj.ud(mu, nu) and returns: r