which involves the square of the constraints in question. Note that formula_337 were infinitely many whereas the master constraint is only one. It is clear that if formula_338 vanishes then so do the infinitely many formula_337's. Conversely, if all the formula_337's vanish then so does formula_338, therefore they are equivalent. The master constraint formula_338 involves an appropriate averaging over all space and so is invariant under spatial diffeomorphisms (it is invariant under spatial "shifts" as it is a summation over all such spatial "shifts" of a quantity that transforms as a scalar). Hence its Poisson bracket with the (smeared) spatial diffeomorphism constraint, formula_343, is simple: