code: def eq4():
      r = Symbol("r")
      e = Rmn.dd(3, 3)
      e = e.subs(nu(r), -lam(r))
      pprint(dsolve(e, lam(r)))
      pprint(dsolve(e, lam(r), "best"))
  
imports: from sympy import exp, Symbol, sin, dsolve, Function, Matrix, Eq, pprint, solve
label_desc: Use image node_id 9 for calling a global function with example usage: eq4() without return types