Let
  Omega = [-20, 20]^3
  r = x -> sqrt(x_0^2 + x_1^2 + x_2^2)
  g = x -> exp(-r(x))
  v = x -> -r(x)^-1
In
  psi = F g
  nu = F v  
  S = < psi | psi >
  V = < psi | nu * psi >
  T = 1/2 * sum_i=0^2 < del_i psi | del_i psi >
  print S, V, T, (T + V)/S
End



