So it's E_gravity that should supply infinite energy, right?
Is it supposed to say something more than "Mass doesn't change"?
Here is what wikipedia says in binding energy
"In bound systems, if the binding energy is removed from the system, it must be subtracted from the mass of the unbound system, simply because this energy has mass, and if subtracted from the system at the time it is bound, will result in removal of mass from the system. System mass is not conserved in this process because the system is not closed during the binding process."
Reference 5 turns out to be hyperphysics page about nuclear binding energy
But wikipedia page has reference to this (pay per view) article as well World Year of Physics: A direct test of E=mc2