Note that, at 1PN, this weak-field metric can also be written as 2 2 g00 = − e2Φ∕c ,gij = e2Ψ∕c δij. Note also that Taylor expanding Eq. 70View Equation yields ∫ Spp = m (v2∕2− ΦN − c2)dt, so that the sum of the classical kinetic and internal actions for a point particle (see Eq. 13View Equation) are now lumped together into the matter action.